Question

Point B has coordinates (4,2). The x-coordinate of point A is - 1. The distance between point A and

point B is 13 units. What are the possible coordinates of point A?

Answer 1

A (-1,-10) ; A (-1,14)

Explanation:

`√((-1-4)^2 + (y-2)^2) = 13 \\ 25 + y^2 + 4 -4y = 169`

y^2 -4y - 140 = 0

Δ/4 = 4 + 140 = 144

y1 = 2 + 12 = 14

y2 = 2 -12= -10