If two lines are perpendicular, which statement must be true?

Question

Their slopes are equal
Their slopes are negative reciprocals
Their slopes are opposites
Their slips are recriprocals

Answer 1

If two lines are perpendicular, the statement that must be true is:

Their slopes are negative reciprocals.

This means that if the slope of one line is \( m \), then the slope of the other line is \( -\frac{1}{m} \).