(2-2i)^5
write in trig form would be easiest
you know how to do that?
I dont think so
you need two number \[r=\sqrt{a^2+b^2}\] and also \(\theta\)
in your case \[r=\sqrt{2^2+2^2}=\sqrt8=2\sqrt2\]
|dw:1416365862786:dw|
So \[\sqrt{8}\] and then if we are working in radians would the angle be 7pi/4 ?
\(\theta\) you have choices if you are working in radians it would \(\frac{7\pi}{4}\) right
What is next?
then it is \[2\sqrt2\left(\cos(\frac{7\pi}{4})+i\sin(\frac{7\pi}{4})\right)\]
then multiply the angle by 5
and also find \((2\sqrt2)^5\)
\[(2\sqrt2)^5=128\sqrt2\]
\[2\sqrt2\left(\cos(\frac{7\pi}{4})+i\sin(\frac{7\pi}{4})\right)]^5=128\sqrt2\left(\cos(\frac{35\pi}{4})+i\sin(\frac{35\pi}{4})\right)\]
right, but my answers are A) 10-10i B) 32-32i C)32-10i D) -128+128i
then convert back
once you convert back you will no doubt get answer D
since \(\cos(\frac{35\pi}{4})=-\frac{1}{\sqrt2}\) etc
Thank you
yw
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