Răspunsuri

Cel mai inteligent răspuns!
2014-10-19T19:44:53+03:00
=\int x(-\cot x)'\ dx=-x\cot x +\int \cot x \ dx

Luam a doua integrala si o rezolvam prin schimbare de variabila
 t=\sin x\\ dt=\cos x \ dx

\int \cot x \ dx=\int\dfrac{\cos x}{\sin x}dx=\int\dfrac{dt}{t}=\ln t=\ln(\sin x).

Raspunsul final e:

-x\cot x+\ln(\sin x)+C

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