Question 34
LociWhat is the locus of points that is equidistant from points P(1, 3) and Q (3, 5)?
- A.y = −x + 6
- B.y = x + 6
- C.y = −x − 6
- D.y = x − 6
Show the answer and explanation
Answer: A (y = −x + 6)
Explanation
The locus is the perpendicular bisector of PQ. The midpoint is (2, 4) and PQ has gradient 1, so the bisector has gradient −1: y − 4 = −(x − 2), i.e. y = −x + 6.