MHB Integral of $\frac{1}{(3+4\sin x)^2}dx$

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The integral of $\frac{1}{(3+4\sin x)^2}dx$ can be approached using the substitution $t = \tan \frac{x}{2}$, which simplifies the expression significantly. This substitution leads to expressions for $dx$, $\sin x$, and $\cos x$ in terms of $t$. While the integral can be expressed in terms of elementary functions, it is noted to be complex. Tools like Wolfram Alpha can provide detailed steps and the final answer for this integral. The discussion emphasizes the utility of substitution methods in solving integrals involving trigonometric functions.
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$\displaystyle \int\frac{1}{(3+4\sin x)^2}dx$
 
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Re: defeinite Integral

jacks said:
$\displaystyle \int\frac{1}{(3+4\sin x)^2}dx$

The 'standard' substition for this type of integral is...

$\displaystyle t= \tan \frac{x}{2} \implies x=2\ \tan^{-1} t \implies dx= \frac{2}{1+t^{2}}\ dt \implies \sin x=\frac{2 t}{1+t^{2}} \implies \cos x= \frac{1-t^{2}}{1+t^{2}}$

Kind regards

$\chi$ $\sigma$
 
Re: defeinite Integral

jacks said:
$\displaystyle \int\frac{1}{(3+4\sin x)^2}dx$

definite/indefinite integral?

This does have an (indefinite) integral in terms of elementary functions, but it is not particularly simple (at least if you assume Wolfram Alpha has chosen a good approach to doing this, it starts with the substitution chisigma proposes in his post. Alpha will give you the steps as well as the final answer so you may as well ask the horses mouth itself)

CB
 
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