3.2+Graphing+Lines

Pratik Sarkar Block-B Date-31/05/09 =__Problem 3.2 and F.U__=

i) y= 3x ii) y= -2x iii) y= 5x-3 iv) y= -x+6 v) y= 2
 * In A-D,consider the following equations.

A) What does each pledge plan mean?** A) The pledge means the following listed below :--:

(i) This statement means you will have to pay $3 per mile. (ii) This statement means you will get $2 per mile. (iii) This statements means that you will get $5 per mile then you will give $3 back from the total. (iv) This statement means that you get $6 but then you will have to give back $1 for every mile. (v) This statement means that it doesn't matter how much distance do you run but you get only $2.

B) PLANS
 * B)** **Without using your graphing calculator, make a table of x and y values for each pledge plan. Use the x-values of 1, 2, 3, 4, and 5. Use your tables to decide which plans are reasonable. Explain how you made your decisions.**
 * **Number of Miles Ran** || PLAN 1 || PLAN 2 || PLAN 3 || PLAN 4 || PLAN 5 ||
 * EQUATIONS

x values || y=3x || y=-2x || y=5x-3 || y=-x+6 || y=2 ||
 * 1 || 3 || -2 || 2 || 5 || 2 ||
 * || 6 || -4 || 7 || 4 || 2 ||
 * 3 || 9 || -6 || 12 || 3 || 2 ||
 * 4 || 12 || -8 || 17 || 2 || 2 ||
 * 5 || 15 || -10 || 22 || 1 || 2 ||

C)
 * C) Graph each pledge plan with a graphing calculator. Use a window that shows the graph clearly. Make a sketch of the graph you see.**

D) The data which shows that the plege plan is increasing or decreasing or going up or down by the same number are the following below ::
 * D) For each pledge plan, tell whether the y values increase, decrease or stay the same as the x value increases. How can you tell from the graph, from the table, from the equation?**

(i) In this equation if x value increases, y value will also increase (by 3 times). (ii) In this equation if x value increases, the y value will decrease (by 2 times). (iii) In this equation if x value increases, the y value will increase. (iv) In this equation if x value increases, the y value will decrease. (v) In this equation if x value increases, the y value will remain the same. = = =__Problem 3.2 F.U__=

1)Plan i: x= (0,0) y= (0,0) Plan ii: x= (0,0) y= (0,0) Plan iii: x= (3/5,0) y= (0,-3) Plan iv: x= (6,0) y= (0,6) Plan v: x= none y= (0,2)
 * 1) For each of the 5 pledge plans, give the coordinates of the points where the line crosses the x and the y axes. Check that the coordinates you give fit the equation. Sometimes the decimal value your calculator gives are only approximations.)**

-2 not -8. Why do you think these students found different answers?**
 * 2) Ali says theat x = -1 makes the equation -8 = -3 + 5x is true. Tamara tries this value in equation. She says Ali is wrong because -3 + 5 (-1) is

2) I think that they found different answers becasue they might not have followed the standard rule (DMAS) for simplification. They might have just looked at the numbers and the sign in the middle which had forced them to have different answers. Ali followed the rule and his answer is correct and Tamara did the addition before the multiplication, hence she has a wrong answer.