Question

Help? I can’t figure out this problem

Answer 1

B

Explanation:

Euler's formula tells you that ...

cos(θ) +sin(θ)·i ≡ e^(i·θ)

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So, for θ = 90° (= π/2 radians), this is ...

cos(π/2) +sin(π/2)·i = 0 +i = i = e^(i·π/2) . . . . . matches choice B