How do you evaluate e^( ( pi)/2 i) - e^( ( 4 pi)/3 i)eπ2ie4π3i using trigonometric functions?

1 Answer
Oct 20, 2016

the answer is =1/2+i(1+sqrt3/2)=12+i(1+32)

Explanation:

Let z= e^(ipi/2)-e^(4ipi/3)z=eiπ2e4iπ3
Use the relation e^(itheta)=costheta + isinthetaeiθ=cosθ+isinθ
So e^(ipi/2)=cos(pi/2)+isin(pi/2)=0+i=ieiπ2=cos(π2)+isin(π2)=0+i=i
and e^(4ipi/3)=cos((4pi)/3)+isin((4pi)/3)=-1/2-isqrt3/2e4iπ3=cos(4π3)+isin(4π3)=12i32
so z=i+1/2+isqrt3/2=1/2+i(1+sqrt3/2)z=i+12+i32=12+i(1+32)