Question

What must be true about the slopes of two perpendicular lines, neither of which is vertical?

Answer 1

Just to let you know, there is no graph or diagram.

Answer 2

The product of the two is -1

Answer 3

Thank you!
Is it possible for you to show me? I understand better that way sometimes.

Answer 4

Example,
a line with the slope -2 is perpendicular to a line with slope 1/2 because

-2*1/2=-1

Answer 5

Okay, thank you! :)