Question

Use Euler's formula to write 3+3i^3 in exponential form.

Answer 1

21−=2(2−)=2cos(−1)+2 sin(−1)

−1+2=−1(2)=−1(cos2+sin2)=cos2+ sin2

Is the above the correct way to write 21− and −1+2 in the form +? I wasn't sure if I could change Euler's formula to =cos()+sin(), where is a constant.

complex-numbers

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edited Mar 6 '17 at 4:38

Richard Ambler

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asked Mar 6 '17 at 3:34

14wml

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1 Answer

1

No. It is not true that =cos()+sin(). Notice that

1=1≠cos()+sin(),

for example consider this at =0.

As a hint for figuring this out, notice that

+=ln(+)

then recall your rules for logarithms to get this to the form (+)ln().