Answer
$\frac{\sqrt{2}}{2} - \frac{\sqrt{2}}{2}i$
Work Step by Step
$1cis\frac{7\pi}{4}$
= $1(cos\frac{7\pi}{4} + isin\frac{7\pi}{4})$
= $\frac{\sqrt{2}}{2} - \frac{\sqrt{2}}{2}i$
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