It's my first post here and I was wondering if someone could help me with evaluating the definite integral $$ \int_0^{\Large\frac{\pi}{4}} \log\left( \cos x\right) \, \mathrm{d}x $$ Thanks in advance, any help would be appreciated.
Evaluating $\int_0^{\large\frac{\pi}{4}} \log\left( \cos x\right) \, \mathrm{d}x $
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$\begingroup$
calculus
integration
trigonometry
definite-integrals
logarithms
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0What did you try ? maybe putting $t=\cos(x)$ would help – 2012-09-19
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0There is an answer, but I cannot say how it is found: http://www.wolframalpha.com/input/?i=Integrate[Log[Cos[x]]%2C{x%2C0%2CPi%2F4}] – 2012-09-19
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0@Siminore: That link is broken; [here](http://wolframalpha.com/input/?i=Integrate[Log[Cos[x]]%2C{x%2C0%2CPi%2F4}])'s one that works. – 2012-09-19
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0@Souvik : You mean 'evaluating'. – 2012-09-19