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| -rw-r--r-- | Problem Set 2.page | 1 |
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diff --git a/Problem Set 2.page b/Problem Set 2.page index fd21bf0..de38296 100644 --- a/Problem Set 2.page +++ b/Problem Set 2.page @@ -40,6 +40,7 @@ $\int_0^{2\pi} |\sin^2(x)|^2 dx = \sum |a_n|^2.$ 2. Since $\sin x = \frac{e^{ix}-e^{-ix}}{2}$, + $\sin^4 x = \frac{{( e^{ix}-e^{-ix} )}^4}{16}$ $= \frac{e^{i 4x}+e^{-i 4x}-4 e^{i 2x} -4 e^{-i 2x}+6}{16}$. |