Integral Calculus: Basic Integration of cotxln(sinx)

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SUMMARY

The integral of the function cot(x)ln(sin(x)) can be evaluated using basic integration techniques without employing integration by parts, partial fractions, or trigonometric substitution. By substituting u = sin(x), the integral simplifies to ∫(ln(u)/u) du, which can be solved directly. The final result is (ln(sin(x)))²/2 + C, where C represents the constant of integration. This method effectively utilizes substitution and the properties of logarithms to arrive at the solution.

PREREQUISITES
  • Understanding of basic integration techniques from Calculus 1
  • Familiarity with substitution methods in integration
  • Knowledge of logarithmic properties and functions
  • Ability to manipulate trigonometric functions, specifically cotangent and sine
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  • Study the properties of logarithmic integration techniques
  • Learn more about substitution methods in integral calculus
  • Explore advanced integration techniques, including integration by parts
  • Practice solving integrals involving trigonometric functions and logarithms
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Students studying calculus, particularly those focusing on integration techniques, as well as educators seeking to enhance their teaching methods for basic integration concepts.

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Homework Statement


evaluate the integral.

Homework Equations


\int (cotx)[ln(sinx)] dx

how would i do this using basic integration techniques from calculus 1? i am not allowed to use, int by parts, partial fractions, trig sub, etc..

The Attempt at a Solution


i tried doing a u=sinx but don't know how to get the cotx.
 
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whatlifeforme said:

Homework Statement


evaluate the integral.

Homework Equations


\int (cotx)[ln(sinx)]

how would i do this using basic integration techniques from calculus 1? i am not allowed to use, int by parts, partial fractions, trig sub, etc..

The Attempt at a Solution


i tried doing a u=sinx but don't know how to get the cotx.
Where's the "dx" ?

\displaystyle \int \cot(x)\ln(\sin(x))\,dx

This may help. \displaystyle \ \cot(x)=\frac{\cos(x)}{\sin(x)}
 
thanks.

so i have:

u=sinx; du=cosx

\int \frac{ln(u)}{u} du

v=lnu; dv=(1/u) du

\int v dv = \frac{v^2}{2} = \frac{(lnu)^2}{2}

= \frac{[ln(sinx)]^2}{2}
 
whatlifeforme said:
thanks.

so i have:

u=sinx; du=cosx

\int \frac{ln(u)}{u} du

v=lnu; dv=(1/u) du

\int v dv = \frac{v^2}{2} = \frac{(lnu)^2}{2}

= \frac{[ln(sinx)]^2}{2}

Looks good to me, other than the +C.
 
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