Recursive Integral Simplification

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The discussion centers on the integral of the form ∫sin^n(x)cos^m(x)dx and its simplification process. The initial expression provided is simplified in a textbook to a form that is more suitable for exam settings. The participant acknowledges that while their original answer is correct, it needs to be expressed in a simpler format to meet academic standards. They also reference an identity that aids in further simplification of the integral. The conversation highlights the importance of presenting mathematical solutions in a concise and standardized manner for assessments.
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\int{\sin^{n}(x)\cos^{m}(x)dx}
=\frac{\sin^{n+1}(x)\cos^{m-1}(x)}{n+1}+\frac{m-1}{n+1}\int{\sin^{n+2}(x)\cos^{m-2}(x)dx}

That was quite easy, but it's the simplification process following this that throws me. My answer is perfectly correct, but it is simplified in the answers (in my maths book) to the following form.

\frac{\sin^{n+1}(x)\cos^{m-1}(x)}{n+m}+\frac{m-1}{n+m}\int{\sin^{n}(x)\cos^{m-2}(x)dx}

The form that I had it in can be used to calculate integrals for specific values of n an m, though in an exam, I believe that I'd have to express it in simpler form to get full marks.

Thanks for the help.
 
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Sorry, forgot to put in the "n" and "m" in the original function.

Any help now?
 
You have the following identity:
\int\sin^{n+2}x\cos^{m-2}xdx=\int\sin^{n}x(1-\cos^{2}x)\cos^{m-2}xdx
 
Thanks. It's really quite simple. I can't believe I missed that!
 
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