Question

Endpoints of segment MN have coordinates (0, 0), (5, 1). The endpoints of segment AB have coordinates (1 1/2 , 2 1/4 ) and (−2 1/4 , k).

What value of k makes these segments perpendicular?

Answer 1

k=21

Explanation:

Find the slope of MN which is 1/5 (use the slope formula)

Use the slope formula for AB using k as y_2

Substitute and you get k=21

21-2.25/-2.25-1.5=-5

The lines are perpendicular because the slopes are the negative reciprocal of one another.