What is the integral of sin^3 theta?

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    Integral Theta
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To solve the integral of sin^3 theta, a substitution involving cos theta is suggested, where cos theta is expressed in terms of t. The discussion highlights the importance of correctly applying trigonometric identities and derivatives. The initial attempt led to an incorrect expression involving cos instead of sin. The final correct form of the integral is noted as sin theta - (1/3)sin^3 theta + C.
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Would very much appreciate a hint on how to start this off.
So far I have cos theta = (1-t^2)/(1+t^2). After squaring this and doing various substitutions, I get (cos theta)^3, which can't be right.
 
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I'm not sure what you're asking but if you want the integral indicated in the title of your post this may help:

\cos^3 \theta = \cos^2 \theta \cos \theta = \left(1-\sin^2 \theta \right) \frac {d \sin \theta}{d\theta}
 
Many thanks. I'll give it a shot.
 
I got cos theta - (1/3)cos^3 theta + C
Does this look right?
 
Almost. It should be sin, not cos.
 
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