Question

Lay down the positions of the points whose polar coordinates are $(-2a,-\frac{2\pi }{3})$

Answer 1

Polar co-ordinates are $(-2a,-\frac{-2\pi }{3})$
Then, $r=-2a$ and $\theta =\frac{-2\pi }{3}$
$x=rcos\theta =(-2a)cos\frac{-2\pi }{3}=a$

$x=rsin\theta =(-2a)sin\frac{-2\pi }{3}=\sqrt{3}a$.
Thus, the Cartesian co-ordinates are $(a,\sqrt{3}a)$.