Difference between revisions of "Applications-of-GeoGebra/C2/Trigonometric-Ratios-and-Graphs/English"
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− | | | + | || '''Slide Number 1''' |
'''Title Slide''' | '''Title Slide''' | ||
− | | | + | || Welcome to this tutorial on '''Trigonometric Ratios and Graphs'''. |
|- | |- | ||
− | | | + | || '''Slide Number 2''' |
'''Learning Objectives''' | '''Learning Objectives''' | ||
− | | | + | || In this '''tutorial''', we will learn how to use '''GeoGebra''' to, |
Calculate '''trigonometric ratios''' | Calculate '''trigonometric ratios''' | ||
Plot corresponding graphs | Plot corresponding graphs | ||
|- | |- | ||
− | | | + | || '''Slide Number 3''' |
'''Pre-requisites''' | '''Pre-requisites''' | ||
| | To follow this '''tutorial''', you should be familiar with | | | To follow this '''tutorial''', you should be familiar with | ||
− | |||
− | + | '''GeoGebra''' interface | |
+ | |||
+ | Previous '''tutorials''' in this series | ||
If not, for relevant '''tutorials''', please visit our website '''www.spoken-tutorial.org'''. | If not, for relevant '''tutorials''', please visit our website '''www.spoken-tutorial.org'''. | ||
|- | |- | ||
− | | | + | ||'''Slide Number 4''' |
'''System Requirement''' | '''System Requirement''' | ||
− | | | + | || Here, I am using |
'''Ubuntu Linux OS version 14.04''' | '''Ubuntu Linux OS version 14.04''' | ||
'''GeoGebra 5.0.388.0-d''' | '''GeoGebra 5.0.388.0-d''' | ||
|- | |- | ||
− | | | + | || Show the '''GeoGebra''' window. |
Point to unit circle and right triangle '''ACB''''. | Point to unit circle and right triangle '''ACB''''. | ||
− | | | + | || I have opened '''GeoGebra''' interface with a '''unit circle''' and a right triangle '''A C B prime.''' |
|- | |- | ||
− | | | + | || '''Slide Number 5''' |
'''Sine function''' | '''Sine function''' | ||
Line 46: | Line 47: | ||
'''Sine''' of an angle is the ratio of the lengths of the opposite side to the '''hypotenuse'''. | '''Sine''' of an angle is the ratio of the lengths of the opposite side to the '''hypotenuse'''. | ||
− | Angle B'AC = | + | Angle B'AC = α<sup>0</sup> =β<sup>0</sup> |
In triangle AB'C, | In triangle AB'C, | ||
Line 53: | Line 54: | ||
Here, '''sin(α) = y co-ordinate''' of point '''B'''' | Here, '''sin(α) = y co-ordinate''' of point '''B'''' | ||
− | | | + | ||'''Sine function''' |
+ | |||
+ | '''Sine''' of an angle is the ratio of the lengths of the opposite side to the '''hypotenuse'''. | ||
'''Angle B prime A C''' is equal to '''alpha degrees''' and to '''beta degrees''' | '''Angle B prime A C''' is equal to '''alpha degrees''' and to '''beta degrees''' | ||
Line 63: | Line 66: | ||
Here, '''sine alpha''' is '''y co-ordinate''' of point '''B prime'''. | Here, '''sine alpha''' is '''y co-ordinate''' of point '''B prime'''. | ||
|- | |- | ||
− | | | + | || Click on '''Options''' menu >> select '''Rounding''' >> '''3 Decimal Places'''. |
− | | | + | || Click on '''Options''' menu. |
Select '''Rounding''' and then '''3 Decimal Places'''. | Select '''Rounding''' and then '''3 Decimal Places'''. | ||
Line 70: | Line 73: | ||
All the ratios will now have 3 decimal places. | All the ratios will now have 3 decimal places. | ||
|- | |- | ||
− | | | + | || '''Setting up the sine function''' |
In '''input bar''', type '''SINE= y(B')/radius'''>> press '''Enter''' | In '''input bar''', type '''SINE= y(B')/radius'''>> press '''Enter''' | ||
− | | | + | || Now let us show '''sine alpha''' values using the '''input bar'''. |
In '''input bar''', type '''SINE''' is equal to '''y B prime''' in parentheses divided by '''radius'''. | In '''input bar''', type '''SINE''' is equal to '''y B prime''' in parentheses divided by '''radius'''. | ||
Line 79: | Line 82: | ||
Press '''Enter'''. | Press '''Enter'''. | ||
|- | |- | ||
− | | | + | || Point to '''sine''' values in '''Algebra''' view. |
− | | | + | || '''Sine''' values are displayed in '''Algebra''' view. |
|- | |- | ||
− | | | + | || Drag '''slider α''' to 0 and then to 360<sup>0</sup>. |
− | | | + | || Drag '''alpha slider''' to 0 and then to 360 '''degrees'''. |
|- | |- | ||
− | | | + | || |
− | | | + | || Observe the change in '''sine''' values in '''Algebra''' view. |
Observe that '''sine''' value remains positive as long as '''y axis''' values are positive. | Observe that '''sine''' value remains positive as long as '''y axis''' values are positive. | ||
|- | |- | ||
− | | | + | || '''Graphing the sine function''' |
Click on '''Point''' >> click on '''Graphics''' view. | Click on '''Point''' >> click on '''Graphics''' view. | ||
− | | | + | || |
Click on '''Point''' tool. | Click on '''Point''' tool. | ||
Click on the screen outside the circle in '''Graphics view.''' | Click on the screen outside the circle in '''Graphics view.''' | ||
|- | |- | ||
− | | | + | || Point to point '''D'''. |
− | | | + | || Point '''D''' appears outside the circle. |
|- | |- | ||
− | | | + | || Drag '''slider α''' to 0. |
− | | | + | || Set '''alpha''' to 0 '''degrees''' on the '''slider'''. |
|- | |- | ||
− | | | + | || Right click on '''D''' >> Select '''Object Properties''' >> '''Color''' tab >> red. |
− | | | + | || Right-click on '''D''' and click on '''Object Properties'''. |
Select '''Color''' tab and choose red. | Select '''Color''' tab and choose red. | ||
|- | |- | ||
− | | | + | || Close the '''Preferences''' window. |
− | | | + | || Close the '''Preferences''' window. |
|- | |- | ||
− | | | + | || Again right-click on '''D''' and check '''Trace On''' option. |
− | | | + | || Again, right-click on '''D''' and check '''Trace On''' option. |
|- | |- | ||
− | | | + | || In '''Algebra''' view, double click on '''D'''. |
− | | | + | || In '''Algebra''' view, double click on '''D'''. |
|- | |- | ||
− | | | + | || Delete '''co-ordinates''' of '''D'''. |
− | | | + | || Delete '''co-ordinates''' of '''D'''. |
|- | |- | ||
− | | | + | || Select '''symbol α''' >> click on the letter '''α''' >> Insert '''α''' as '''x co-ordinate''' of '''D'''. |
− | | | + | || Select '''symbol alpha''', click on the letter '''alpha'''. |
Insert '''alpha''' as '''x co-ordinate''' of '''D'''. | Insert '''alpha''' as '''x co-ordinate''' of '''D'''. | ||
|- | |- | ||
− | | | + | || Type '''SINE''' as '''y co-ordinate''' of '''D''' >> press '''Enter''' |
− | | | + | || Type '''SINE''' as '''y co-ordinate''' of '''D''', and press '''Enter'''. |
|- | |- | ||
− | | | + | || Point to '''D (α, SINE)''' in the '''Algebra''' view. |
− | | | + | || '''D''' has been changed to '''alpha comma SINE'''. |
|- | |- | ||
− | | | + | || |
− | | | + | || '''GeoGebra''' will convert '''alpha''' into '''radians'''. |
The '''alpha''' value in '''radians''' is the '''x co-ordinate''' of '''D'''. | The '''alpha''' value in '''radians''' is the '''x co-ordinate''' of '''D'''. | ||
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This will make '''D''' trace the '''sine function''' as you change '''angle alpha'''. | This will make '''D''' trace the '''sine function''' as you change '''angle alpha'''. | ||
|- | |- | ||
− | | | + | || |
− | | | + | || We want to see 2 '''pi radians''' along the positive side of the '''x axis'''. |
|- | |- | ||
− | | | + | || Under '''Move Graphics View''', click once on '''Zoom Out''' and then twice in '''Graphics''' view. |
− | | | + | || Under '''Move Graphics View''', click once on '''Zoom Out''' and then twice in '''Graphics''' view. |
|- | |- | ||
− | | | + | || Click on '''Move Graphics View''' tool. |
Click on '''Graphics''' background and when hand '''symbol''' appears, move '''Graphics''' view. | Click on '''Graphics''' background and when hand '''symbol''' appears, move '''Graphics''' view. | ||
− | | | + | || Click on '''Move Graphics View''' tool. |
Click on '''Graphics''' background and when hand '''symbol''' appears, move '''Graphics''' view. | Click on '''Graphics''' background and when hand '''symbol''' appears, move '''Graphics''' view. | ||
|- | |- | ||
− | | | + | || Point to circle and 2 '''pi radians''' on right side of origin on '''x axis'''. |
− | | | You should see the circle and 2 '''pi radians''' along positive side of '''x axis'''. | + | || You should see the circle and 2 '''pi radians''' along positive side of '''x axis'''. |
|- | |- | ||
− | | | + | || Drag '''slider α''' from 0<sup>0</sup> to 360<sup>0</sup>. |
− | | | + | || Increase '''alpha''' on the '''slider''' from 0 to 360 '''degrees''' 2 '''pi radians'''. |
|- | |- | ||
− | | | + | || Point to traces of '''D'''. |
− | | | + | || Point '''D''' will trace the '''sine function''' graph. |
|- | |- | ||
− | | | + | || Point to '''SINE''' values in '''Algebra''' view. |
− | | | + | || '''Sine''' values remain positive as long as '''y''' values are positive. |
|- | |- | ||
− | | | + | || In '''input bar''', type '''d(x) = sin(x)''' >> press '''Enter'''. |
− | | | + | || In '''input bar''', type '''d x''' in parentheses is equal to '''sin x''' in parentheses and press '''Enter'''. |
|- | |- | ||
− | | | + | || Point to the '''sine function''' graph beyond '''−2π''' and '''+2π''' '''radians'''. |
− | | | + | || '''Sine function''' will be graphed beyond '''minus 2 pi''' and '''plus 2 pi radians'''. |
|- | |- | ||
− | | | + | || Click on and move '''Graphics''' view to see '''d of x''' beyond '''minus''' and '''plus''' 2 '''pi radians'''. |
− | | | + | || Click on and move '''Graphics''' view to see '''d of x''' beyond '''minus''' 2 '''pi''' and '''plus''' 2 '''pi radians'''. |
|- | |- | ||
− | | | + | || Point to '''D'''. |
− | | | + | || Note that this will erase traces of '''D'''. |
|- | |- | ||
− | | | + | || Click on and move '''Graphics''' view to see circle and '''plus''' 2 '''pi radian''' along '''x axis'''. |
− | | | + | || Click on and move '''Graphics''' view to see circle and '''plus''' 2 '''pi radians''' along '''x axis'''. |
|- | |- | ||
− | | | + | || Drag '''slider α''' to 0 '''degrees''' to see traces of '''D'''. |
− | | | + | || Again drag '''slider alpha''' to 0 '''degrees''' to see traces of '''D'''. |
|- | |- | ||
− | | | + | || Point to '''d(x)''' and traces of '''D'''. |
− | | | + | || Compare '''d of x''' with traces of '''D'''. |
|- | |- | ||
− | | | + | || '''Slide Number 6''' |
'''Cosine function''' | '''Cosine function''' | ||
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In this unit circle, cos(α) = x co-ordinate of point B' | In this unit circle, cos(α) = x co-ordinate of point B' | ||
− | | | + | || |
'''Cosine''' of an angle is the ratio of the lengths of the adjacent side to the '''hypotenuse'''. | '''Cosine''' of an angle is the ratio of the lengths of the adjacent side to the '''hypotenuse'''. | ||
Line 206: | Line 209: | ||
In this '''unit circle, cos alpha''' corresponds to '''x co-ordinate''' of point '''B prime.''' | In this '''unit circle, cos alpha''' corresponds to '''x co-ordinate''' of point '''B prime.''' | ||
|- | |- | ||
− | | | + | || Right-click on point '''D''' and uncheck '''Trace On''' option. |
− | | | + | || Right-click on point '''D''' and uncheck '''Trace On''' option. |
|- | |- | ||
− | | | + | || Click on and move '''Graphics''' view slightly to erase traces of '''D'''. |
− | | | + | || Click on and move '''Graphics''' view slightly to erase traces of '''D'''. |
|- | |- | ||
− | | | + | || In '''input bar''', type '''COSINE = x(B')/radius''' >> press '''Enter'''. |
− | | | + | || In '''input bar''', type the following line. |
'''COSINE''' is equal to '''x B prime''' in parentheses divided by '''radius'''. | '''COSINE''' is equal to '''x B prime''' in parentheses divided by '''radius'''. | ||
Line 220: | Line 223: | ||
Press '''Enter'''. | Press '''Enter'''. | ||
|- | |- | ||
− | | | + | || Point to '''cosine''' value in '''Algebra''' view. |
− | | | + | || '''Cosine''' value is displayed in '''Algebra''' view. |
|- | |- | ||
− | | | + | || Drag '''slider α''' from 0<sup>0</sup> to 360<sup>0</sup>. |
− | | | + | || Drag '''slider alpha''' from 0 to 360 '''degrees'''. |
|- | |- | ||
− | | | + | || Point to the '''cosine''' value in the '''Algebra''' view. |
− | | | + | || Observe how '''cosine''' values change in '''Algebra''' view. |
|- | |- | ||
− | | | + | || Point to positive side of '''x axis'''. |
− | | | + | || Note how '''cosine''' remains positive as long as '''x axis''' values are positive. |
|- | |- | ||
− | | | + | || '''Graphing the cosine function''' |
Click on '''Point''' tool and click outside the circle. | Click on '''Point''' tool and click outside the circle. | ||
− | | | + | || |
Click on '''Point''' tool and click outside the circle. | Click on '''Point''' tool and click outside the circle. | ||
'''Point E''' appears outside the circle. | '''Point E''' appears outside the circle. | ||
|- | |- | ||
− | | | + | || Drag '''slider α''' to 0<sup>0</sup>. |
− | | | + | || Drag '''slider alpha''' to 0 '''degrees'''. |
|- | |- | ||
− | | | + | || Right click on '''E''' >> Select '''Object Properties'''>> '''Color''' tab >> Brown. |
− | | | + | || Right-click on '''E''', click on '''Object Properties'''. |
Select '''Color''' tab and choose brown. | Select '''Color''' tab and choose brown. | ||
|- | |- | ||
− | | | + | || Close the '''Preferences''' window. |
− | | | + | || Close the '''Preferences''' window. |
|- | |- | ||
− | | | + | || Right-click on '''E,''' check '''Trace On''' option. |
− | | | + | || Right-click on '''E''', check '''Trace On''' option. |
|- | |- | ||
− | | | + | || In '''Algebra''' view, double click on '''E'''. |
− | | | + | || In '''Algebra''' view, double click on '''E'''. |
|- | |- | ||
− | | | + | || Delete '''co-ordinates''' of '''E'''. |
− | | | + | || Delete '''co-ordinates''' of '''E'''. |
|- | |- | ||
− | | | + | || Select '''symbol α''' >> click on the letter '''α''' >> insert '''α''' as '''x co-ordinate''' of '''E''' |
− | | | + | || Select '''symbol alpha''', click on the letter '''alpha'''. |
Insert '''alpha''' as '''x co-ordinate''' of '''E'''. | Insert '''alpha''' as '''x co-ordinate''' of '''E'''. | ||
|- | |- | ||
− | | | + | || Type '''COSINE''' instead of the '''y co-ordinate''' of '''E''' >> press '''Enter''' |
− | | | + | || Type '''COSINE''' instead of '''y co-ordinate''' of '''E''', and press '''Enter'''. |
|- | |- | ||
− | | | + | || Point to '''E''' ('''α, COSINE''') in '''Algebra''' view. |
− | | | + | || '''E''' has been changed to '''alpha comma COSINE'''. |
|- | |- | ||
− | | | + | || Drag '''slider α''' from 0<sup>0</sup> to 360<sup>0</sup>. |
− | | | + | || Drag '''slider alpha''' from 0 to 360 '''degrees'''. |
|- | |- | ||
− | | | + | || Point to traces of '''E'''. |
− | | | + | || Point '''E''' will trace the '''cosine function''' graph. |
|- | |- | ||
− | | | + | || In '''input bar,''' type '''e(x) = cos(x)''' >> press '''Enter'''. |
− | | | + | || In input bar, type '''e x in parentheses is equal to cos x in parentheses'''. |
Press '''Enter'''. | Press '''Enter'''. | ||
|- | |- | ||
− | | | + | || Point to '''cosine function e(x)'''. |
− | | | + | || '''Cosine function e of x''' will be graphed beyond '''minus''' 2 '''pi''' and '''plus''' 2 '''pi radians'''. |
|- | |- | ||
− | | | + | || Click on and move '''Graphics''' view to see '''e(x''') beyond '''−2π''' and '''+2π radians'''. |
− | | | + | || Click and move '''Graphics''' view to see '''e of x''' beyond '''minus''' 2 '''pi''' and '''plus''' 2 '''pi radians'''. |
|- | |- | ||
− | | | + | || Point to '''E'''. |
− | | | + | || This will erase traces of '''E'''. |
|- | |- | ||
− | | | + | || Click on and move '''Graphics''' view to see +2 '''pi radians''' along '''x axis'''. |
− | | | + | || Click on and move '''Graphics '''view to see '''plus''' 2 '''pi radians''' along '''x axis'''. |
|- | |- | ||
− | | | + | || Drag '''slider α''' to 0 '''degrees''' to see traces of '''E'''. |
− | | | + | || Again drag '''slider alpha''' to 0 '''degrees''' to see traces of '''E'''. |
|- | |- | ||
− | | | + | || Point to '''e(x)''' and traces of '''E'''. |
− | | | + | || Compare the graph of '''e of x''' with traces of '''E'''. |
|- | |- | ||
− | | | + | || Right-click on point '''E''' >> Uncheck '''Trace on''' |
− | | | + | || Right-click on '''E''' and uncheck '''Trace On''' option. |
|- | |- | ||
− | | | + | || Click in and move '''Graphics''' view slightly to erase traces of '''E'''. |
− | | | + | || Click on and move '''Graphics''' view slightly to erase traces of '''E'''. |
|- | |- | ||
− | | | + | || '''Slide Number 7''' |
'''Tangent function''' | '''Tangent function''' | ||
Line 315: | Line 318: | ||
tan(α) = y(B')/x(B') | tan(α) = y(B')/x(B') | ||
− | | | + | || |
'''Tangent''' of an angle is the ratio of lengths of the opposite side to the adjacent side. | '''Tangent''' of an angle is the ratio of lengths of the opposite side to the adjacent side. | ||
Line 322: | Line 325: | ||
'''Tan alpha''' is also the ratio of the '''y co-ordinate''' to '''x co-ordinate''' of '''B prime'''. | '''Tan alpha''' is also the ratio of the '''y co-ordinate''' to '''x co-ordinate''' of '''B prime'''. | ||
|- | |- | ||
− | | | + | || In '''input bar''', type '''TANGENT = y(B')/x(B')''' >> press '''Enter'''. |
− | | | + | || In '''input bar''', type the following line. |
'''TANGENT''' is equal to '''y B prime''' in parentheses divided by '''x B prime''' in parentheses. | '''TANGENT''' is equal to '''y B prime''' in parentheses divided by '''x B prime''' in parentheses. | ||
Line 329: | Line 332: | ||
Press '''Enter'''. | Press '''Enter'''. | ||
|- | |- | ||
− | | | + | || Point to the '''tangent''' value in '''Algebra''' view. |
− | | | + | || '''Tangent''' value is displayed in '''Algebra''' view. |
|- | |- | ||
− | | | + | || '''Setting up the tangent function''' |
− | Drag '''alpha slider''' from | + | Drag '''alpha slider''' from 0<sup>0</sup> to 360<sup>0</sup>. |
− | | | + | || Drag '''alpha slider''' from 0 to 360 '''degrees'''. |
|- | |- | ||
− | | | + | || Point to the '''Tangent''' values in''' Algebra''' view. |
− | | | + | || Observe how '''tangent''' values change in '''Algebra''' view. |
|- | |- | ||
− | | | + | || Click on''' Point''' tool and click outside the circle. |
− | | | + | || Click on '''Point''' tool and click outside the circle. |
|- | |- | ||
− | | | + | || Point to point '''F'''. |
− | | | + | || Point '''F''' appears outside the circle. |
|- | |- | ||
− | | | + | || Drag '''α slider''' to 0. |
− | | | + | || Set '''alpha''' to 0 '''degrees''' on the '''slider'''. |
|- | |- | ||
− | | | + | || Right-click on '''F''' >> Select '''Object Properties''' >> '''Color''' tab >> green. |
− | | | + | || Right-click on '''F''' and select '''Object Properties'''. |
Select '''Color''' tab and choose green. | Select '''Color''' tab and choose green. | ||
|- | |- | ||
− | | | + | || Close the '''Preferences''' window. |
− | | | + | || Close the '''Preferences''' window. |
|- | |- | ||
− | | | + | || Again right-click on '''F''', check '''Trace On''' option. |
− | | | + | || Again right-click on '''F''', check '''Trace On''' option. |
|- | |- | ||
− | | | + | || In '''Algebra''' view, scroll down and double click on '''F'''. |
− | | | + | || In '''Algebra''' view, scroll down and double click on '''F'''. |
|- | |- | ||
− | | | + | || Delete '''co-ordinates''' of '''F'''. |
− | | | + | || Delete '''co-ordinates''' of '''F'''. |
|- | |- | ||
− | | | + | || Select '''symbol α''' >> click on the letter '''α''' >> insert '''α''' as '''x co-ordinate''' of '''F''' |
− | | | + | || Select '''symbol alpha''', click on the letter '''alpha'''. |
Insert '''alpha''' as '''x co-ordinate''' of '''F'''. | Insert '''alpha''' as '''x co-ordinate''' of '''F'''. | ||
|- | |- | ||
− | | | + | || Type '''TANGENT''' as '''y co-ordinate''' of '''F''' >> press '''Enter''' |
− | | | + | || Type '''TANGENT''' as '''y co-ordinate''' of '''F''', and press '''Enter'''. |
|- | |- | ||
− | | | + | || Point to '''F''' ('''α, TANGENT''') in the '''Algebra''' view. |
− | | | + | || '''F''' has been changed to '''alpha comma TANGENT'''. |
|- | |- | ||
− | | | + | || Point to '''F'''. |
− | | | + | || Point '''F''' will trace the '''tangent function''' graph as '''alpha''' value changes. |
|- | |- | ||
− | | | + | || Drag '''α slider''' value from 0<sup>0</sup> to 360<sup>0</sup>. |
− | | | + | || Increase '''alpha''' on the '''slider''' from 0 to 360 '''degrees''' 2 '''pi radians'''. |
|- | |- | ||
− | | | + | || Point to traces of '''F''' from 0 to π/2 '''radians'''. |
− | | | + | || '''F''' increases from '''origin''' to '''infinity'''. |
Note '''vertical asymptote''' at '''pi''' divided by 2 '''radians'''. | Note '''vertical asymptote''' at '''pi''' divided by 2 '''radians'''. | ||
|- | |- | ||
− | | | + | || Point to the graphs. |
− | | | + | || '''Tangent''' value is plus '''infinity''' at '''pi''' divided by 2 '''radians'''. |
It is minus '''infinity''' at 3 '''pi''' divided by 2 '''radians'''. | It is minus '''infinity''' at 3 '''pi''' divided by 2 '''radians'''. | ||
|- | |- | ||
− | | | + | || Type '''f(x) = tan(x)''' in '''input bar''' >> press '''Enter'''. |
− | | | + | || In '''input bar''', type '''f x in parentheses is equal to tan x in parentheses''' and press '''Enter'''. |
|- | |- | ||
− | | | + | || Point to '''f(x)'''. |
− | | | + | || The '''tangent function''' is graphed beyond minus 2 '''pi''' and plus 2 '''pi radians'''. |
|- | |- | ||
− | | | + | || Click on and move '''Graphics''' view beyond '''−2π''' and '''+2π radians'''. |
− | | | + | || Click on and move '''Graphics''' view to see graph of '''f of x''' beyond '''minus''' 2 '''pi''' and '''plus''' 2 '''pi radians'''. |
|- | |- | ||
− | | | + | || Click on and move '''Graphics''' background to see plus 2 '''pi radians''' along '''x axis'''. |
− | | | + | || Click on and move '''Graphics''' view to see '''plus 2''' '''pi radians''' along '''x axis'''. |
|- | |- | ||
− | | | + | || Drag '''α slider''' value from 360<sup>0</sup> to 0<sup>0</sup>. |
− | | | + | || Drag '''slider alpha''' back to 0 '''degrees''' to see traces of '''F'''. |
|- | |- | ||
− | | | + | || Point to '''f(x)''' and traces of '''F'''. |
− | | | + | || Also compare the '''tangent function f of x''' with traces of '''F'''. |
|- | |- | ||
− | | | + | || |
− | | | + | || Let us summarize. |
|- | |- | ||
− | | | + | || '''Slide Number 8''' |
'''Summary''' | '''Summary''' | ||
− | | | + | || In this tutorial, we have learnt |
how to use '''GeoGebra''' to calculate and graph '''sin alpha''', '''cos alpha''' and '''tan alpha''' | how to use '''GeoGebra''' to calculate and graph '''sin alpha''', '''cos alpha''' and '''tan alpha''' | ||
|- | |- | ||
− | | | + | || '''Slide Number 9''' |
'''Assignment''' | '''Assignment''' | ||
− | | | + | || Assignment |
Try these steps to graph '''secant, cosecant''' and '''cotangent functions'''. | Try these steps to graph '''secant, cosecant''' and '''cotangent functions'''. | ||
Line 432: | Line 435: | ||
Analyze the link between '''sine''' and '''cosine''' values for '''supplementary angles'''. | Analyze the link between '''sine''' and '''cosine''' values for '''supplementary angles'''. | ||
|- | |- | ||
− | | '''Slide Number 10''' | + | || '''Slide Number 10''' |
'''About Spoken Tutorial project''' | '''About Spoken Tutorial project''' | ||
− | | | + | || The video at the following link summarizes the '''Spoken Tutorial Project'''. |
Please download and watch it. | Please download and watch it. | ||
|- | |- | ||
− | | | + | || '''Slide Number 11''' |
'''Spoken Tutorial workshops''' | '''Spoken Tutorial workshops''' | ||
− | | | + | || The '''Spoken Tutorial Project '''team conducts workshops and gives certificates. |
For more details, please write to us. | For more details, please write to us. | ||
|- | |- | ||
− | | | + | || '''Slide Number 12''' |
'''Forum for specific questions:''' | '''Forum for specific questions:''' | ||
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Someone from our team will answer them. | Someone from our team will answer them. | ||
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− | | | + | || '''Slide Number 13''' |
'''Acknowledgement''' | '''Acknowledgement''' | ||
− | | | + | || '''Spoken Tutorial Project''' is funded by '''NMEICT, MHRD''', Government of India. |
More information on this mission is available at this link. | More information on this mission is available at this link. | ||
|- | |- | ||
− | | | + | || |
− | | | + | || This is '''Vidhya Iyer''' from '''IIT Bombay''' signing off. |
Thank you for joining. | Thank you for joining. | ||
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|} | |} |
Revision as of 21:09, 20 May 2018
Visual Cue | Narration |
Slide Number 1
Title Slide |
Welcome to this tutorial on Trigonometric Ratios and Graphs. |
Slide Number 2
Learning Objectives |
In this tutorial, we will learn how to use GeoGebra to,
Calculate trigonometric ratios Plot corresponding graphs |
Slide Number 3
Pre-requisites |
To follow this tutorial, you should be familiar with
GeoGebra interface Previous tutorials in this series If not, for relevant tutorials, please visit our website www.spoken-tutorial.org. |
Slide Number 4
System Requirement |
Here, I am using
Ubuntu Linux OS version 14.04 GeoGebra 5.0.388.0-d |
Show the GeoGebra window.
Point to unit circle and right triangle ACB'. |
I have opened GeoGebra interface with a unit circle and a right triangle A C B prime. |
Slide Number 5
Sine function Sine of an angle is the ratio of the lengths of the opposite side to the hypotenuse. Angle B'AC = α0 =β0 In triangle AB'C, sin(α) = B'C/AB' = y(B')/radius Here, sin(α) = y co-ordinate of point B' |
Sine function
Sine of an angle is the ratio of the lengths of the opposite side to the hypotenuse. Angle B prime A C is equal to alpha degrees and to beta degrees In triangle A B prime C, sine alpha equals ratio of the lengths B prime C to A B prime. This is also equal to ratio of y co-ordinate of B prime to radius. Here, sine alpha is y co-ordinate of point B prime. |
Click on Options menu >> select Rounding >> 3 Decimal Places. | Click on Options menu.
Select Rounding and then 3 Decimal Places. All the ratios will now have 3 decimal places. |
Setting up the sine function
In input bar, type SINE= y(B')/radius>> press Enter |
Now let us show sine alpha values using the input bar.
In input bar, type SINE is equal to y B prime in parentheses divided by radius. Press Enter. |
Point to sine values in Algebra view. | Sine values are displayed in Algebra view. |
Drag slider α to 0 and then to 3600. | Drag alpha slider to 0 and then to 360 degrees. |
Observe the change in sine values in Algebra view.
Observe that sine value remains positive as long as y axis values are positive. | |
Graphing the sine function
Click on Point >> click on Graphics view. |
Click on Point tool. Click on the screen outside the circle in Graphics view. |
Point to point D. | Point D appears outside the circle. |
Drag slider α to 0. | Set alpha to 0 degrees on the slider. |
Right click on D >> Select Object Properties >> Color tab >> red. | Right-click on D and click on Object Properties.
Select Color tab and choose red. |
Close the Preferences window. | Close the Preferences window. |
Again right-click on D and check Trace On option. | Again, right-click on D and check Trace On option. |
In Algebra view, double click on D. | In Algebra view, double click on D. |
Delete co-ordinates of D. | Delete co-ordinates of D. |
Select symbol α >> click on the letter α >> Insert α as x co-ordinate of D. | Select symbol alpha, click on the letter alpha.
Insert alpha as x co-ordinate of D. |
Type SINE as y co-ordinate of D >> press Enter | Type SINE as y co-ordinate of D, and press Enter. |
Point to D (α, SINE) in the Algebra view. | D has been changed to alpha comma SINE. |
GeoGebra will convert alpha into radians.
The alpha value in radians is the x co-ordinate of D. Its y co-ordinate is the SINE value of alpha. This will make D trace the sine function as you change angle alpha. | |
We want to see 2 pi radians along the positive side of the x axis. | |
Under Move Graphics View, click once on Zoom Out and then twice in Graphics view. | Under Move Graphics View, click once on Zoom Out and then twice in Graphics view. |
Click on Move Graphics View tool.
Click on Graphics background and when hand symbol appears, move Graphics view. |
Click on Move Graphics View tool.
Click on Graphics background and when hand symbol appears, move Graphics view. |
Point to circle and 2 pi radians on right side of origin on x axis. | You should see the circle and 2 pi radians along positive side of x axis. |
Drag slider α from 00 to 3600. | Increase alpha on the slider from 0 to 360 degrees 2 pi radians. |
Point to traces of D. | Point D will trace the sine function graph. |
Point to SINE values in Algebra view. | Sine values remain positive as long as y values are positive. |
In input bar, type d(x) = sin(x) >> press Enter. | In input bar, type d x in parentheses is equal to sin x in parentheses and press Enter. |
Point to the sine function graph beyond −2π and +2π radians. | Sine function will be graphed beyond minus 2 pi and plus 2 pi radians. |
Click on and move Graphics view to see d of x beyond minus and plus 2 pi radians. | Click on and move Graphics view to see d of x beyond minus 2 pi and plus 2 pi radians. |
Point to D. | Note that this will erase traces of D. |
Click on and move Graphics view to see circle and plus 2 pi radian along x axis. | Click on and move Graphics view to see circle and plus 2 pi radians along x axis. |
Drag slider α to 0 degrees to see traces of D. | Again drag slider alpha to 0 degrees to see traces of D. |
Point to d(x) and traces of D. | Compare d of x with traces of D. |
Slide Number 6
Cosine function Cosine of an angle is the ratio of the lengths of the adjacent side to the hypotenuse. cos(α) = AC/AB' = x(B')/radius In this unit circle, cos(α) = x co-ordinate of point B' |
Cosine of an angle is the ratio of the lengths of the adjacent side to the hypotenuse. Cos alpha is equal to the following ratios. Length of AC to length of AB prime and x co-ordinate of B prime to radius. In this unit circle, cos alpha corresponds to x co-ordinate of point B prime. |
Right-click on point D and uncheck Trace On option. | Right-click on point D and uncheck Trace On option. |
Click on and move Graphics view slightly to erase traces of D. | Click on and move Graphics view slightly to erase traces of D. |
In input bar, type COSINE = x(B')/radius >> press Enter. | In input bar, type the following line.
COSINE is equal to x B prime in parentheses divided by radius. Press Enter. |
Point to cosine value in Algebra view. | Cosine value is displayed in Algebra view. |
Drag slider α from 00 to 3600. | Drag slider alpha from 0 to 360 degrees. |
Point to the cosine value in the Algebra view. | Observe how cosine values change in Algebra view. |
Point to positive side of x axis. | Note how cosine remains positive as long as x axis values are positive. |
Graphing the cosine function
Click on Point tool and click outside the circle. |
Click on Point tool and click outside the circle. Point E appears outside the circle. |
Drag slider α to 00. | Drag slider alpha to 0 degrees. |
Right click on E >> Select Object Properties>> Color tab >> Brown. | Right-click on E, click on Object Properties.
Select Color tab and choose brown. |
Close the Preferences window. | Close the Preferences window. |
Right-click on E, check Trace On option. | Right-click on E, check Trace On option. |
In Algebra view, double click on E. | In Algebra view, double click on E. |
Delete co-ordinates of E. | Delete co-ordinates of E. |
Select symbol α >> click on the letter α >> insert α as x co-ordinate of E | Select symbol alpha, click on the letter alpha.
Insert alpha as x co-ordinate of E. |
Type COSINE instead of the y co-ordinate of E >> press Enter | Type COSINE instead of y co-ordinate of E, and press Enter. |
Point to E (α, COSINE) in Algebra view. | E has been changed to alpha comma COSINE. |
Drag slider α from 00 to 3600. | Drag slider alpha from 0 to 360 degrees. |
Point to traces of E. | Point E will trace the cosine function graph. |
In input bar, type e(x) = cos(x) >> press Enter. | In input bar, type e x in parentheses is equal to cos x in parentheses.
Press Enter. |
Point to cosine function e(x). | Cosine function e of x will be graphed beyond minus 2 pi and plus 2 pi radians. |
Click on and move Graphics view to see e(x) beyond −2π and +2π radians. | Click and move Graphics view to see e of x beyond minus 2 pi and plus 2 pi radians. |
Point to E. | This will erase traces of E. |
Click on and move Graphics view to see +2 pi radians along x axis. | Click on and move Graphics view to see plus 2 pi radians along x axis. |
Drag slider α to 0 degrees to see traces of E. | Again drag slider alpha to 0 degrees to see traces of E. |
Point to e(x) and traces of E. | Compare the graph of e of x with traces of E. |
Right-click on point E >> Uncheck Trace on | Right-click on E and uncheck Trace On option. |
Click in and move Graphics view slightly to erase traces of E. | Click on and move Graphics view slightly to erase traces of E. |
Slide Number 7
Tangent function Tangent of an angle is the ratio of lengths of the opposite side to the adjacent side tan(α) = sin(α)/cos(α) = B'C/AC tan(α) = y(B')/x(B') |
Tangent of an angle is the ratio of lengths of the opposite side to the adjacent side. Tan alpha is the ratio of sine alpha to cos alpha and the ratio of lengths of B prime C to AC. Tan alpha is also the ratio of the y co-ordinate to x co-ordinate of B prime. |
In input bar, type TANGENT = y(B')/x(B') >> press Enter. | In input bar, type the following line.
TANGENT is equal to y B prime in parentheses divided by x B prime in parentheses. Press Enter. |
Point to the tangent value in Algebra view. | Tangent value is displayed in Algebra view. |
Setting up the tangent function
Drag alpha slider from 00 to 3600. |
Drag alpha slider from 0 to 360 degrees. |
Point to the Tangent values in Algebra view. | Observe how tangent values change in Algebra view. |
Click on Point tool and click outside the circle. | Click on Point tool and click outside the circle. |
Point to point F. | Point F appears outside the circle. |
Drag α slider to 0. | Set alpha to 0 degrees on the slider. |
Right-click on F >> Select Object Properties >> Color tab >> green. | Right-click on F and select Object Properties.
Select Color tab and choose green. |
Close the Preferences window. | Close the Preferences window. |
Again right-click on F, check Trace On option. | Again right-click on F, check Trace On option. |
In Algebra view, scroll down and double click on F. | In Algebra view, scroll down and double click on F. |
Delete co-ordinates of F. | Delete co-ordinates of F. |
Select symbol α >> click on the letter α >> insert α as x co-ordinate of F | Select symbol alpha, click on the letter alpha.
Insert alpha as x co-ordinate of F. |
Type TANGENT as y co-ordinate of F >> press Enter | Type TANGENT as y co-ordinate of F, and press Enter. |
Point to F (α, TANGENT) in the Algebra view. | F has been changed to alpha comma TANGENT. |
Point to F. | Point F will trace the tangent function graph as alpha value changes. |
Drag α slider value from 00 to 3600. | Increase alpha on the slider from 0 to 360 degrees 2 pi radians. |
Point to traces of F from 0 to π/2 radians. | F increases from origin to infinity.
Note vertical asymptote at pi divided by 2 radians. |
Point to the graphs. | Tangent value is plus infinity at pi divided by 2 radians.
It is minus infinity at 3 pi divided by 2 radians. |
Type f(x) = tan(x) in input bar >> press Enter. | In input bar, type f x in parentheses is equal to tan x in parentheses and press Enter. |
Point to f(x). | The tangent function is graphed beyond minus 2 pi and plus 2 pi radians. |
Click on and move Graphics view beyond −2π and +2π radians. | Click on and move Graphics view to see graph of f of x beyond minus 2 pi and plus 2 pi radians. |
Click on and move Graphics background to see plus 2 pi radians along x axis. | Click on and move Graphics view to see plus 2 pi radians along x axis. |
Drag α slider value from 3600 to 00. | Drag slider alpha back to 0 degrees to see traces of F. |
Point to f(x) and traces of F. | Also compare the tangent function f of x with traces of F. |
Let us summarize. | |
Slide Number 8
Summary |
In this tutorial, we have learnt
how to use GeoGebra to calculate and graph sin alpha, cos alpha and tan alpha |
Slide Number 9
Assignment |
Assignment
Try these steps to graph secant, cosecant and cotangent functions. Analyze the link between sine values for supplementary angles (angles whose sum is 180 degrees). Analyze the link between sine and cosine values for supplementary angles. |
Slide Number 10
About Spoken Tutorial project |
The video at the following link summarizes the Spoken Tutorial Project.
Please download and watch it. |
Slide Number 11
Spoken Tutorial workshops |
The Spoken Tutorial Project team conducts workshops and gives certificates.
For more details, please write to us. |
Slide Number 12
Forum for specific questions: Do you have questions in THIS Spoken Tutorial? Please visit this site. Choose the minute and second where you have the question. Explain your question briefly. Someone from our team will answer them. |
Please post your timed queries on this forum. |
Slide Number 13
Acknowledgement |
Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India.
More information on this mission is available at this link. |
This is Vidhya Iyer from IIT Bombay signing off.
Thank you for joining. |