How do you evaluate e7π4ie5π8i using trigonometric functions?

1 Answer
Mar 23, 2016

e7π4ie5π8i1.08981.631i

Explanation:

eiθ=cosθ+isinθ

e7π4i=cos(7π4)+isin(7π4)

e5π8i=cos(5π8)+isin(5π8)

e7π4ie5π8i=[cos(7π4)+isin(7π4)][cos(5π8)+isin(5π8)]

e7π4ie5π8i=[cos(7π4)cos(5π8)]+i[sin(7π4)sin(5π8)]

e7π4ie5π8i1.08981.631i