determine weather it is parallel, perpendicular, or neither

Question

Determine whether the lines through each pair of points are parallel, perpendicular, or neither.

(-6, 8) and (-10, 14); (9, -2) and (6, -4)

Answer 1

Let's find the gradient of the first set of points

 

14-8 / (-10+6)

 

-6/4

 

=-3/2

 

the second set of points

 

(-4+2) / (6-9)

 

=  2/3

 

Since one is a negative reciprocal of the other the lines are perpendicular.