\(\int_{\frac{\pi}{4}}^{\frac{3\pi}{4}}\frac{1}{1+\cos x}dx=\)

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\(\int_{\frac{\pi}{4}}^{\frac{3\pi}{4}}\frac{1}{1+\cos x}dx=\int_{\frac{\pi}{4}}^{\frac{3\pi}{4}}\frac{1-\cos x}{\sin^2xdx}\)