Question

The Cartesian co-ordinates of $\left( - 2,\frac{2\pi}{3} \right)$ will be

• A. (1, $\sqrt{3}$)
• B. ($\sqrt{3}$, 1)
• C. (1, – $\sqrt{3}$)
• D. (–1, $\sqrt{3}$)

Answer 1

Answer: (C)

(1, – $\sqrt{3}$)

Answer 2

$\left( - 2,\frac{2\pi}{3} \right)$

x = r cos q and y = r sin q

x = (–2) cos $\frac{2\pi}{3}$ and y = (–2) sin $\frac{2\pi}{3}$

x = (–2) $\left( - \frac{1}{2} \right)$ and y = (–2) $\left( \frac{\sqrt{3}}{2} \right)$ $\left( 1, - \sqrt{3} \right)$