Question

Find the Cartesian co-ordinates of points whose polar coordinates are :

(1,180°)

Answer 1

(r, θ) = (1, 180°)

Using x = r cos θ and y = r sin θ, where (x, y) are the required cartesian co-ordinates, we get

x = 1(cos 180°) and y = 1(sin 180°)

∴ x = –1 and y = 0

∴ the required cartesian co-ordinates are (–1, 0).