Question Number 43418 by Raj Singh last updated on 10/Sep/18
Answered by tanmay.chaudhury50@gmail.com last updated on 10/Sep/18
$$\int\frac{{cosxdx}}{{sinxcosx}+\mathrm{1}} \\ $$$$\int\frac{\mathrm{2}{cosx}}{\mathrm{2}{cosxsinx}+\mathrm{2}}{dx} \\ $$$$\int\frac{{cosx}+{sinx}+{cosx}−{sinx}}{\mathrm{1}+\left({sinx}+{cosx}\right)^{\mathrm{2}} }{dx} \\ $$$$\int\frac{{cosx}−{sinx}}{\mathrm{1}+\left({sinx}+{cosx}\right)^{\mathrm{2}} }{dx}+\int\frac{{cosx}+{sinx}}{\mathrm{2}+\mathrm{2}{sinxcosx}}{dx} \\ $$$$\int\frac{{d}\left({sinx}+{cosx}\right)}{\mathrm{1}+\left({sinx}+{cosx}\right)}−\int\frac{\left({cosx}+{sinx}\right){dx}}{−\mathrm{3}+\mathrm{1}−\mathrm{2}{sinxcosx}} \\ $$$$\int\frac{{d}\left({sinx}+{cosx}\right)}{\mathrm{1}+\left({sinx}+{cosx}\right)^{\mathrm{2}} }−\int\frac{{d}\left({sinx}−{cosx}\right)}{−\mathrm{3}+\left({sinx}−{cosx}\right)^{\mathrm{2}} } \\ $$$${formula}\:\int\frac{{dx}}{{x}^{\mathrm{2}} +{a}^{\mathrm{2}} }=\frac{\mathrm{1}}{{a}}{tan}^{−} \left(\frac{{x}}{{a}}\right) \\ $$$$\int\frac{{dx}}{{x}^{\mathrm{2}} −{b}^{\mathrm{2}} } \\ $$$$=\frac{\mathrm{1}}{\mathrm{2}{b}}\int\frac{\left({x}+{b}\right)−\left({x}−{b}\right)}{\left({x}+{b}\right)\left({x}−{b}\right)}{dx} \\ $$$$=\frac{\mathrm{1}}{\mathrm{2}{b}}\left[\int\frac{{dx}}{{x}−{b}}−\int\frac{{dx}}{{x}+{b}}\right] \\ $$$$=\frac{\mathrm{1}}{\mathrm{2}{b}}{ln}\mid\frac{{x}−{b}}{{x}+{b}}\mid \\ $$$${so}\:{ans}\:{is} \\ $$$${tan}^{−\mathrm{1}} \left({sinx}+{cosx}\right)−\frac{\mathrm{1}}{\mathrm{2}\sqrt{\mathrm{3}}\:}{ln}\mid\frac{{sinx}−{cosx}−\sqrt{\mathrm{3}}\:}{{sinx}−{cosx}+\sqrt{\mathrm{3}}}\mid+{c} \\ $$$$ \\ $$