if z = x+yi prove that: abs(e^z)=e^x so I can show that e^z = e^x * cisy, I'm not sure what how the absolute value will change this.
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Two big hints. $\displaystyle \left| {cis(t)} \right| = \left| {\cos (t) + i\sin (t)} \right| = \sqrt {\cos ^2 (t) + \sin ^2 (t)} = ?$ $\displaystyle \left| {zw} \right| = \left| z \right|\left| w \right|$
$\displaystyle e^{z} = e^{x}(\cos y + i \sin y) $. Thus $\displaystyle |e^{z}| = |e^{x}| \cdot |\cos y + i \sin y| = e^{x} $. As Plato hinted, the modulus of the second term is $\displaystyle 1 $.
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