Question

Which equation represents a line perpendicular to a line that passes through (-2,4) and (1,-5)

Answer 1

I know how to get the slope of the line you are looking for. There are an infinite variety of equations that will be perpendicular to the line between the 2 given points. You have to provide us the answer choices. Do you know how to get the slope of the line through (-2,4) and (1,-5)?

Answer 2

the answer choices are
y=-3x+2
y= -1/3x +2
y= 1/3x+2
y= 3x+2

Answer 3

Do you know how to get the slope of the line through (-2,4) and (1,-5)?

Answer 4

to find the slope of a line you have to use the slope formula :
slope(m) = (y2 - y1) / (x2 - x1)
(-2,4) x1 = -2, y1 = 4
(1,-5) x2 = 1, y2 = -5

slope(m) = (-5 - 4)/ (1 - (-2)
m = -9/(1 + 2)
m = -9/3
m = -3

are you understand this ?

Answer 5

Is the slope -9/3? If so, then I know how to find slope lol
I did m= y2-y1/x2-x1

Answer 6

the slope is -3, because -9/3 can be simplified. However, we are looking for a perpendicular line. That means the slope is going to be the negative reciprocal of -3. All that means is that you take the slope, "flip" it, and change the sign.
So -3 (-3/1) will then be 1/3 for your slope. Do you understand ?

Answer 7

Yes. So that means that the perpendicular slope would be -1/3x + 2?

Answer 8

lets check.....we will now use point slope formula because we have the slope and you can use either of your points.
y - y1 = m(x - x1) using slope 1/3 and points (-2,4)
y - 4 = 1/3(x - (-2)
y - 4 = 1/3(x + 2)
y - 4 = 1/3x + 2/3
y = 1/3x + 2/3 + 4
y = 1/3x + 2/3 + 12/3
y = 1/3x + 14/3

I must be doing something wrong because I am not getting any of your answer choices.

Answer 9

let me try the other points (1,-5)
y - y1 = m(x - x1)
y - (-5) = 1/3(x - 1)
y + 5 = 1/3x - 1/3
y = 1/3x - 1/3 - 5
y = 1/3x - 5/15 - 75/15
y = 1/3x - 80/15
y = 1/3x - 16/3

I am not sure of the answer

Answer 10

I have no idea, I'm doing this in a math packet

Answer 11

I am not getting any of your answer choices

Answer 12

@ivettef365 ...can you help

Answer 13

The perpendicular line doesn't have to go through one of the endpoints. You're assuming it does when you construct your point slope form. It just has to have a slope of 1/3. Only answer C has a slope of 1/3. That's the answer

Answer 14

@thomaster ...please help

Answer 15

well...I suppose BangkokGarrett is right...C is the only one that has a slope of 1/3

Answer 16

Thank you! :)