Question

If you multiply the slopes of two perpendicular lines, the product is −1.

(As long as neither line is vertical.)

Answer 1

True

Explanation:

We can prove this by modeling the slope of a line as x, and since perpendicular lines have the opposite reciprocal slope of the first line, its slope will be
`(-1)/(x)`.

From here, you multiply the two slopes together, which is
`(x)/(1)*(-1)/(x)`. Simplifying this expression gives
`(-x)/(x)`, which is equal to -1 when you cancel out x.