Assignment 18

You did well on these questions.

Let me know if anything is unclear, and include specifics about what you do and do not understand.

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15:50:50 query 2.4.30 (was 2.3.24). Slope 4/3, point (-3,2) Give the three points you found on this line and explain how you obtained them.

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RESPONSE --> Slope can be equal to 4/3 or -4/-3, so I would start with the first point (-3, 2) and move 3 units x, and 4 units y so that would be (-3+3) and (2+4)= (0,6) Then I would move -3 units x and -4 units y from (-3,2)= (-3-3) and (2-4)= (-6,-2). Looking at what I have, I would move from (0,6) 3 units x and 4 units y (0+3) (6+4)= (3,10)

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15:51:02 STUDENT SOLUTION: (-3,2) slope 4/3. Move 3 units in the x direction, 4 in the y direction to get ((-3+3), (2+4)), which simplifies to (0,6) (-3,2) slope 4/3 = -4/-3 so move -3 units in the x direction and -4 in the y direction to get ((-3-3), (2-4)) which simplifies to (-6,-2) From (0,6) with slope 4/3 we move 4 units in the y direction and 3 in the x direction to get ((0+3), (6+4)), which simplifies to (3,10). The three points I obtained are (-6,-2), (0,6), (3,10).

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RESPONSE --> ok

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15:57:03 query 2.4.36 (was 2.3.30). Line thru (-1,1) and (2,2) **** Give the equation of the line and explain how you found the equation.

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RESPONSE --> I think I would first find the slope m= y2-y1/ x2-x1= 2-1/2-(-1)= 1/3. Then I would use point slope: y-y1=m(x-x1)= y-1= 1/3(x+1)= y= 1/3 x+4/3.

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15:57:15 STUDENT SOLUTION: The slope is m = (y2 - y1) / (x2 - x1) = (2-1)/(2- -1) = 1/3. Point-slope form gives us y - y1 = m (x - x1); using m = 1/3 and (x1, y1) = (-1, 1) we get y-1=1/3(x+1), which can be solved for y to obtain y = 1/3 x + 4/3.

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RESPONSE --> ok

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15:59:22 **** query 2.4.46 (was 2.3.40). x-int -4, y-int 4 **** What is the equation of the line through the given points and how did you find the equation?

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RESPONSE --> x intercept= (4,0) y int.= (0,4) slope= y2-y1/x2-x1= 4-0/0-(-4)= 4/4= m=1 y=mx+b y=1x+4= y=x+4

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15:59:36 STUDENT SOLUTION: The two points are (0, 4) and (4, 0). The slope is therefore m=rise / run = (4-0)/(0+4) = 1. The slope-intercept form is therefore y = m x + b = 1 x + 4, simplifying to y=x+4.

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RESPONSE --> ok

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16:00:52 **** query 2.4.56 (was 2.4.48). y = 2x + 1/2. **** What are the slope and the y-intercept of your line and how did you find them?

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RESPONSE --> y= mx+b, so the slope here is 2. Substitute 0 for x to get the y intercept= y=2(0)+1/2 y=1/2

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16:01:26 ** the y intercept occurs where x = 0, which happens when y = 2 (0) + 1/2 or y = 1/2. So the y-intercept is (0, 1/2). The slope is m = 2.**

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RESPONSE --> I forgot to put the y int. in correct point form (0,1/2), but I see my mistake now.

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