How do you multiply e3π2ie3π2i in trigonometric form?

1 Answer
Mar 27, 2016

e3π2ie3π2i=1

Explanation:

As eiθ=cosθ+isinθ, we have

e3π2i=cos(3π2)+isin(3π2).

Hence, e3π2ie3π2i=

{cos(3π2)+isin(3π2)}{cos(3π2)+isin(3π2)} or

= {cos2(3π2)+i2sin2(3π2)+2isin(3π2)cos(3π2)}

= {cos2(3π2)+(1)sin2(3π2)+i(2sin(3π2)cos(3π2))}

= {(cos2(3π2)sin2(3π2))+i(2sin(3π2)cos(3π2))}

= cos(2×3π2)+isin(2×3π2)

= cos3π+isin3π

= 1+i×0=1