calc question..

Question

Change to algebraic form: 3(cos 90° + i sin 0°)

a.1–3i

b. -3i

c. 3i

Answer 1

I don't see the correct answer in your choices.

cos 90 = 0

sin 0 = 0

3(cos 90° + i sin 0°) = 3 (0 + i 0) = 0