Question 1
Coordinate GeometryGiven that the straight lines kx − 5y + 6 = 0 and mx + ny − 1 = 0 are parallel, find a relationship connecting the constants m, n and k.
- A.5n − km = 0
- B.kn + 5m = 0
- C.5n + km = 0
- D.kn − 5m = 0
Show the answer and explanation
Answer: B (kn + 5m = 0)
Explanation
The gradients are k/5 and −m/n. Parallel lines have equal gradients, so k/5 = −m/n, giving kn = −5m, i.e. kn + 5m = 0.