Respuesta :

sqdancefan

Answer:

  B

Step-by-step 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