Question

Lines p and q are perpendicular. If the slope of line p is 2, what is the slope of line q?

A.
B. -
C. -2
D. 2

Answer 1

If the slope of one line is 2, and the other line is perpendicular, the other line's slope is the negative reciprocal of 2, or -1/2 :)

Answer 2

For this case we define the following variables:

• mp: slope of the line p
• mq: slope of the line q

By definition, since the lines are perpendicular, it follows that:

`mp * mq = -1`

Substituting values we have:

`2 * mq = -1`

From here, we clear the value of the slope of the line q:

`mq = - \frac {1} {2}`

Answer:

The slope of line is:

`mq = - \frac {1} {2}`