Question 29
Coordinate GeometryIf the lines 3x + 2y = 4 and 2x − ky = 1 are perpendicular, find the value of constant k.
- A.3
- B.2/3
- C.−2/3
- D.−2
Show the answer and explanation
Answer: A (3)
Explanation
The gradients are −3/2 and 2/k. Perpendicular lines need (−3/2)(2/k) = −1, so −3/k = −1 and k = 3.