Answer: m 1 × m 2 = -1.
- A m<sub>1</sub> = m<sub>2</sub>
- B m<sub>1</sub> + m<sub>2</sub> = 0
- C m<sub>1</sub> × m<sub>2</sub> = -1
- D m<sub>1</sub> × m<sub>2</sub> = 1
Correct answer: C. m<sub>1</sub> × m<sub>2</sub> = -1
Explanation: Perpendicular lines: m<sub>1</sub> × m<sub>2</sub> = -1. If one slope is 2, the perpendicular slope is -1/2.
The slope of a line is the ratio of vertical change (rise) to horizontal change (run) between any two points on it - equivalently, the tangent of the angle θ the line makes with the positive x-axis.