How do you multiply e^(( pi )/ 4 i) * e^( 3 pi/2 i ) eπ4ie3π2i in trigonometric form?

1 Answer
Mar 2, 2018

The answer is =sqrt2/2(1-i)=22(1i)

Explanation:

Apply Euler's Identity

e^(itheta)=costheta+isinthetaeiθ=cosθ+isinθ

i^2=-1i2=1

Therefore,

e^(pi/4i)=cos(pi/4)+isin(pi/4)=sqrt2/2+isqrt2/2=sqrt2/2(1+i)eπ4i=cos(π4)+isin(π4)=22+i22=22(1+i)

e^(3/2pii)=cos(3/2pi)+isin(3/2pi)=0-ie32πi=cos(32π)+isin(32π)=0i

So,

z=e^(pi/4i)*e^(3/2pii)=sqrt2/2(1+i)*(-i)=sqrt2/2(-i-i^2)z=eπ4ie32πi=22(1+i)(i)=22(ii2)

=sqrt2/2(1-i)=22(1i)

"Verification"Verification

z=(cosphi+isinphi)=sqrt2/2(1-i)z=(cosϕ+isinϕ)=22(1i)

cosphi=sqrt2/2cosϕ=22

sinphi=-sqrt2/2sinϕ=22

phi=-pi/4ϕ=π4, [2pi][2π]

z=e^(pi/4i)*e^(3/2pii)=e^((pi/4+3/2pi)i)=e^(7/4pii)=e^(-1/4pii)z=eπ4ie32πi=e(π4+32π)i=e74πi=e14πi