Answer:
A
Step-by-step explanation:
In step 3, Mark forgot to multiply 5 · 5, so he ended up with 5 in the denominator instead of 5 · 5 = 25
A. $1250; $1500 because if you bought something for $1250 and sold it for $1500 you would be gaining $250
Write i in trigonometric form. Since |i| = 1 and arg(i) = π/2, we have
i = exp(i π/2) = cos(π/2) + i sin(π/2)
By DeMoivre's theorem,
i² = exp(i π/2)² = exp(i π) = cos(π) + i sin(π)
and it follows that i² = -1 since cos(π) = -1 and sin(π) = 0.
