Question

(See diagram) The gradient of the line joining the origin to the point A is 1/2. The distance between A and the origin is sqrt 2205. What are the coordinates of A?

Answer 1

(42, 21) or (–42, –21)

Explanation:

let A(x, y), A on line 2y = x

distance

x² + y² = 2205

(2y)² + y² = 2205

y² = 441

y = ±21

x = ±42