Write the complex number in the form a + bi.
-$3 \left( \cos 270 ^ { \circ } + i \sin 270 ^ { \circ } \right)$
A) $- 3 \mathrm { i }$
B) 3
C) $- 3$
D) $3 \mathrm { i }$

Name: Write the complex number in the form a + bi. -$3 \left( \cos 270 ^ { \circ } + i \sin 270 ^ { \circ } \right)$ A) $- 3 \mathrm { i }$ B) 3 C) $- 3$ D) $3 \mathrm { i }$
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Question

Quizplus · Accepted Answer

The given complex number is in polar form. At $270^\circ$, $\cos 270^\circ = 0$ and $\sin 270^\circ = -1$. Thus, $3(0 + i(-1)) = -3i$.

Write the Complex Number in the Form a + Bi 3(cos⁡270∘+isin⁡270∘)3 \left( \cos 270 ^ { \circ } + i \sin 270 ^ { \circ } \right)3(cos270∘+isin270∘)

Write the Complex Number in the Form a + Bi $3 \left( \cos 270 ^ { \circ } + i \sin 270 ^ { \circ } \right)$