PhET/C2/GraphingLines/English
Visual Cue  Narration 
Slide Number 1
Title Slide 
Welcome to this tutorial on Graphing Lines simulation. 
Slide Number 2
Learning Objectives Demonstrate an interactive PhET simulation, Graphing Lines 
In this tutorial, we will demonstrate, Graphing Lines, an interactive PhET simulation. 
Slide Number 3
Prerequisites 
To follow this tutorial,
Learner should be familiar with topics in high school mathematics. 
Slide Number 4
System Requirements Ubuntu Linux OS version 14.04 Java version 1.7.0 Firefox Web Browser 53. 02.2 
Here I am using,
Ubuntu Linux OS version 14.04 Java version 1.7 Firefox Web Browser version 53.02.2 
Slide Number 5
Learning Goals 
Using this simulation we will learn,
About Cartesian coordinate system How to calculate the slope of a graphed line To save the plotted lines 
Slide Number 6
Learning Goals 
How to change the slope and intercept of the line
How, changing variables in a linear equation will affect the line. 
Slide Number 7
Linear Equation y=mx+b point to m and b. 
An equation with two variables x and y is a Linear equation. y=mx+b
Here m is slope of the line and b is intercept. Slope signifies rate of change of y value with respect to x value. yintercept is y value when x=0 
Let us begin the demonstration.  
Slide Number 8
Link for PhET simulation 
Use the given link to download the simulation. 
Point to the file in Downloads folder.  I have already downloaded Graphing Lines simulation to my Downloads folder. 
Right click on graphinglines_en.html file.
Select Open With Firefox Web Browser option. Point to the browser address. 
To open the simulation, right click on graphinglines_en.html file.
Select the option, Open With Firefox Web Browser. File opens in the browser. 
Cursor on the interface.  This is the interface of Graphing Lines simulation. 
Point to each screen.  The interface has four screens,
Slope SlopeIntercept PointSlope and Line Game. 
Click on Slope screen.  Click on Slope screen. 
Point to the graph.  Screen has a Cartesian coordinate system with x and y axes. 
Point to the formula box

On the right side, formula box shows formula to find slope of the line. 
point to the input buttons.
Point to the default values. 
To calculate the slope, we can input values for y2, y1 and x2, x1.
Default values of y2, y1 are 4 and 2. And x2, x1 are 3 and 1. 
Point to the graph and slope.  A graph is plotted using the default values.
Here we can see, Slope is 1. 
Point to the buttons.  We can change the values of y2, y1 and x2, x1 using up and down arrow buttons. 
Point to the Save Line option
Point to Erase Lines option. 
Plotted line can be saved using Save Line button. 
Click on the red minus sign.
Click on green plus button. 
We can hide the formula box, by clicking on red minus sign.
To show the box click on green plus button. 
Point to Slope, Hide lines, Hide grid check boxes.  Below the formula box, we have Slope, Hide lines and Hide grid check boxes. 
Point to the check boxes.  If we click on, Hide lines and Hide grid check boxes, graph and grid are hidden.
Automatically, Slope check box is disabled. 
Uncheck, Hide lines and Hide grid check boxes  Let's uncheck Hide lines and Hide grid check boxes to enable Slope check box. 
Point to the Graph and slope.  Notice that Graph displays value of the slope.
Observe that on moving purple and yellow points, x1, y1 and x2, y2 values can be changed. 
Point to purple and yellow points on the line. Click and drag them on the line. 
As we move the points, slope of the line changes.
Observe the change in values of x and y in the formula box. 
Point to the Point tools (gray boxes displaying point coordinates).

At the bottom of the screen, we have gray boxes to display coordinates of a point.
These gray boxes are called as Point tools. 
Drag and place the Point tools on purple and yellow points.
Point to the coordinates. 
Drag and place Point tools on purple and yellow points to see the coordinates. 
Drag the Point tools  Drag the Point tools to the bottom. 
Drag the purple point.
Drag one of the Point tool 
Drag the purple point to coincide with origin (0, 0).
Drag one of the Point tool and place it on the origin. 
Drag yellow point
Point to slope. 
Drag yellow point to coincide with (5,5).
Observe that slope of the line is 1. 
Click on Save Line button.  Click on Save Line button in the formula box.
Line is saved. 
Drag the yellow point to (2,8).
Drag the point tool and place it on yellow point. 
Drag the yellow point to (2,8).
Drag the point tool and place it on yellow point. This confirms that yellow point is at(2,8). 
Point to Slope  Now Slope is 4. 
Click on Save Line in right panel.  Click on Save Line in the formula box.
Line is saved. 
Drag the yellow point to (5,5).
Drag the point tool. 
Drag the yellow point to (5,5).
Drag and place Point tool on yellow point. 
Point to Slope  Now Slope is 1. 
Click on Save Line in right panel.  Click on Save Line in the formula box.
Line is saved. 
Drag the yellow point to (2,8) x=2, y=8
Point to the slope. 
Drag the point tool back to place.
Drag the yellow point to (2,8). 
Point to Slope  Here Slope is 4. 
Click Save Line.  Click on Save Line.
Line is saved 
Notice the 6 lines in graph, on left panel.  We have drawn 4 lines with different slopes.
Notice that steepness is related to slope. 
Slide Number 9
Assignment 
As an assignment,
Find when slope is zero and when it is undefined. Give an explanation. 
Cursor on SlopeIntercept screen.  Now let us explore SlopeIntercept screen at the bottom of the interface. 
Click on SlopeIntercept screen.
Point to the line. 
Click on SlopeIntercept screen.
Screen opens with a line y= 2/3x+1. 
Point to intercept.  Here intercept value is 1. 
Point to m and b.  In this screen we can change the values of 'm' and 'b'. 
Drag the purple point on the line.
Point to the intercept. 
Drag the purple point on y axis.
Notice that purple point represents the intercept. When we move the purple point, intercept for the line changes. 
Move the blue point on the line.
Point to the blue point. 
The blue point is free to move across the graph.
When we move the blue point, slope of the line changes. 
Click on Reset button.
Click on Save Line 
Click on Reset button to reset the simulation.
Click on Save Line. Line is saved. 
Change the value to 3.
Drag the Point tool to the blue point. Point to slope and intercept. 
Change the numerator value of m from 2 to 3 in the formula box.
Notice that slope is 1 while Intercept still remains 1. 
Point the line.
Point to the intercept. Click on Save Line 
Now adjust m again to 2/3 and increase b value to 4.
Notice that, the new line is parallel to the first line but intercepts yaxis at 4. Click on Save Line. 
Point to saved line.  Line is saved. 
Point to the line.
Click on Save Line in the formula box.

Change b value to 2
Click on Save Line. Line is saved. 
Point to 3 parallel lines with different points.  We have 3 parallel lines intercepting y axis at 3 different points. 
Click on Reset button.  Click on Reset button to reset the simulation. 
Point to b value.
Point to the line. 
Let us change b value to zero.
Notice that purple point is at the origin. 
Point to the origin.  Line now passes through the origin. 
Click on y=x and y=x check boxes.
Point to the lines. 
Click on y=x and y=x check boxes below the slope.
Notice that we have three lines passing through the origin. 
Point to PointSlope screen.  Let us now move on to PointSlope screen. 
Click on PointSlope at the bottom of the screen.  Click on PointSlope at the bottom of the interface. 
Cursor on the screen.  In PointSlope screen, a set of (x,y) values are substituted in the equation.
In this method, x and y values are defined. 
point to the formula box.  For a given value of (x, y), m can be calculated using the formula, yy1 = m(xx1) 
Point to purple point and drag the point tool to see coordinates.  The Generic point (x1,y1) is represented by the purple point. 
Drag the Point tool to the purple point  Drag the Point tool to the purple point to see its coordinates. 
Drag the Point tool back to its place.  Drag the Point tool back to its place. 
Demonstrate moving line.
Point the red cross mark in the formula box. 
Drag the purple and blue points freely across the graph to modify the equation of the line.
Drag and place purple point to (5,0). 
Drag the blue point to (5,5).  Then drag the blue point to (5,5). 
Point to yaxis and slope.  Notice that line is parallel to yaxis and slope is undefined. 
Click on Save line.  Click on Save line. Line is saved. 
Drag the purple point along the xaxis.
Point to Slope . 
Drag the purple point along the xaxis.
Notice that Slope is undefined all along the xaxis. 
move the cursor to Line Game screen.  Now let us move on to Line Game screen. 
Go to Line Game tab
Point to the levels. 
Click on Line Game screen.
Line Game screen has 6 difficulty levels, to play. These games will test the knowledge gained using this simulation. 
Point to Timer and Sound buttons  It has a Timer and Sound buttons at the bottom of the screen. 
Click on each game >> explore.  Click on each game and explore. 
Slide Number 10
Summary 
Lets summarize.
In this tutorial, we have learnt, About Graphing Lines, an interactive PhET simulation. 
Slide Number 11
Summary 
Using this simulation, we have learnt,
About Cartesian coordinate system with x and y axes. How to calculate the slope of a graphed line. To save the plotted lines 
Slide Number 12
Summary 
How to change the slope and intercept of the line How changing variables in a linear equation will affect the line. 
Slide Number 13  As an assignment
1. Using SlopeIntercept screen, find when the value of slope is 1. 2. Using PointSlope screen, find in which quadrants slope is positive. 
Slide Number 14
About the Spoken Tutorial Project 
The video at the following link summarizes the Spoken Tutorial project.
Please download and watch it. 
Slide Number 15
Spoken Tutorial workshops 
The Spoken Tutorial Project team:
conducts workshops using spoken tutorials and gives certificates on passing online tests. For more details, please write to us. 
Slide Number 16
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 in this forum. 
Slide Number 17
Acknowledgement 
This project is partially funded by Pandit Madan Malaviya National Mission on Teachers and Teaching. 
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Acknowledgement 
Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India.
More information on this mission is available at this link. 
This tutorial is contributed by Spoken tutorial team IIT Bombay.
Thank you for joining. 