How do you simplify [sqrt2(cos((7pi)/4)+isin((7pi)/4))]div[sqrt2/2(cos((3pi)/4)+isin((3pi)/4))] and express the result in rectangular form?

2 Answers
Apr 21, 2018

[sqrt2(cos((7pi)/4)+isin((7pi)/4))]div[sqrt2/2(cos((3pi)/4)+isin((3pi)/4))]

=[sqrt2(cos((7pi)/4)+isin((7pi)/4))]/[sqrt2/2(cos((3pi)/4)+isin((3pi)/4))]

=[2(cos((7pi)/4)+isin((7pi)/4))]/[(cos((3pi)/4)+isin((3pi)/4))]

=[2e^(i(7pi)/4)]/[e^(i(3pi)/4)]

=2e^(i((7pi)/4-(3pi)/4)]

=2e^(ipi)

=2(cospi+isinpi)

=2(-1+i*0)=-2+i*0

Apr 21, 2018

The answer is -2+0i

Explanation:

Two divide two complex numbers, we divide their moduli and subtract their arguments.

So our number will have modulus

sqrt2/(sqrt2/2)=1/(1/2)=2

and argument of

7/4pi-3/4pi=4/4pi=pi

So our number will be

2(cospi+isinpi)=2(-1+0i)=-2+0i