Write the complex number in rectangular form.
-$\operatorname { cis } 210$
A) $- \frac { \sqrt { 3 } } { 2 } - \frac { 1 } { 2 } \mathrm { i }$
B) $\frac { \sqrt { 3 } } { 2 } - \frac { 1 } { 2 } \mathrm { i }$
C) $- \frac { 1 } { 2 } + \frac { - 1 } { 2 } \mathrm { i }$
D) $- \frac { \sqrt { 3 } } { 2 } + \frac { 1 } { 2 } \mathrm { i }$

Question

Quizplus · Accepted Answer

The complex number $\operatorname{cis} 210$ can be written in rectangular form as $cos(210^\circ) + i \cdot sin(210^\circ)$. At $210^\circ$, $cos(210^\circ) = -\frac{\sqrt{3}}{2}$ and $sin(210^\circ) = -\frac{1}{2}$, resulting in $-\frac{\sqrt{3}}{2} - \frac{1}{2}i$.

Write the Complex Number in Rectangular Form cis⁡210\operatorname { cis } 210cis210

Write the Complex Number in Rectangular Form $\operatorname { cis } 210$