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**1. Use Euler's identity to prove that cos**

^{3}(t)=3/4cos(t)+1/4cos(3t)**2. e**

^{i[tex]\theta[/tex]}=cos(theta)+i*sin(theta)**3. 3/4cos(t)+1/2cos(3t)=3/4((e**

^{it}+e^{-it})/2)+1/4((e^{i3t}+e^{-i3t})/2)-
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- Thread starter roldy
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Pengwuino

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Got it. Thanks a bunch. That was pretty simple, just overlooked the simple substitution.

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