On a coordinate plane, line A B goes through (negative 2, 4) and (0, negative 4). Point Z is at (0, 2).
Which point is on the line that passes through point Z and is perpendicular to line AB?

(–4, 1)
(1, –2 )
(2, 0)
(4, 4)

Question

On a coordinate plane, line A B goes through (negative 2, 4) and (0, negative 4). Point Z is at (0, 2).
Which point is on the line that passes through point Z and is perpendicular to line AB?

(–4, 1)
(1, –2 )
(2, 0)
(4, 4)

dude · Answer

Okay so you first want to create the equation of a line for line AB

Find the slope by using $\frac{y_2-y_1}{x_2-x_1}$

This will give you the slope, luckily one point they gave you was the y-intercept, so you can just add it to the equation of a line y=mx+b

To find a line perpendicular just negate the slope of the line you have

Ex. If your slope is 1, then it would turn into -1 for the second equation

The z value is a y intercept so you can just substitute it into the second equation