Solving $\frac{1}{\cos(x)-1}dx$ - Any Hints?

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SUMMARY

The integral of the function $\frac{1}{\cos(x)-1}dx$ can be simplified using trigonometric identities. By rewriting the expression as $\int \frac{\cos x + 1}{-\sin^2 x} dx$, it can be transformed into $\int -\cot x \csc x - \csc^2 x dx$. The integral can also be expressed as $-\frac{1}{2}\int \frac{dx}{\sin^{2}\frac{x}{2}}$ through a substitution, leading to a solution using tabulated integrals.

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  • Understanding of trigonometric identities, specifically $\sin^2 x$ and $\cos^2 x$ relationships.
  • Familiarity with integration techniques, including substitution and integration of trigonometric functions.
  • Knowledge of the properties of $\cot x$ and $\csc x$ functions.
  • Experience with tabulated integrals for solving complex integrals.
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  • Study the derivation and application of trigonometric identities in integration.
  • Learn about integration techniques involving substitution in trigonometric integrals.
  • Explore the properties and applications of $\cot x$ and $\csc x$ in calculus.
  • Review tabulated integrals and their use in solving complex integrals.
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bolas
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I need help with this one:

\frac{1}{\cos(x)-1}dx

I know there must be a way to rewrite it so that i can use 1 - cos^2 = sin^2. I've tried to multiply by cosx + 1 / cosx + 1 and that gets me further but the answer doesn't seem to be the same maybe because of simplification?

Any hints?

thanks
 
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The integral is equal to:

\int \frac {\cos x + 1}{-\sin ^2 x} dx I suggest you use some trigonometric identities to change it into
\int - \cot x \csc x - \csc ^2 x dx
 
\int \frac{dx}{\cos x-1}=-\int \frac{dx}{1-\cos x}=-\frac{1}{2}\int \frac{dx}{\sin^{2}\frac{x}{2}}

use a simple substitution and a tabulated integral to get the answer.
 
\\T=[\sqrt\frac{\a}{g}]\In\fract{a+\sqrt{a^2-b^2}}{b}
 
Last edited:
\\T={\sqrt\frac{\a}{g}}\In\fract{a+\sqrt{a^2-b^2}}{b}
 

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