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Category: Integration

Question-144168

Question Number 144168 by bekzodjumayev last updated on 22/Jun/21 Answered by Olaf_Thorendsen last updated on 22/Jun/21 $$\mathrm{F}\left({x}\right)\:=\:\int\frac{{dx}}{\mathrm{arccos}{x}} \\ $$$$\mathrm{Let}\:{x}\:=\:\mathrm{cos}\theta \\ $$$$\mathrm{F}\left({x}\right)\:=\:−\int\frac{\mathrm{sin}\theta}{\theta}\:{d}\theta\:=\:−\mathrm{Si}\left(\theta\right)+\mathrm{C} \\ $$$$\mathrm{F}\left({x}\right)\:=\:−\mathrm{Si}\left(\mathrm{arccos}{x}\right)+\mathrm{C} \\ $$…

cos-x-cos-x-cos-x-cos-x-sin-x-dx-

Question Number 144142 by bobhans last updated on 22/Jun/21 $$\:\int\:\frac{\sqrt{\mathrm{cos}\:\mathrm{x}+\sqrt{\mathrm{cos}\:\mathrm{x}+\sqrt{\mathrm{cos}\:\mathrm{x}+\sqrt{\mathrm{cos}\:\mathrm{x}+\sqrt{…}}}}}}{\mathrm{sin}\:\mathrm{x}}\:\mathrm{dx} \\ $$ Answered by liberty last updated on 22/Jun/21 $$\sqrt{\mathrm{cos}\:\mathrm{x}+\sqrt{\mathrm{cos}\:\mathrm{x}+\sqrt{\mathrm{cos}\:\mathrm{x}+\sqrt{…}}}}\:=\:\ell\: \\ $$$$\sqrt{\mathrm{cos}\:\mathrm{x}+\ell}\:=\:\ell\:\Rightarrow\ell^{\mathrm{2}} −\ell−\mathrm{cos}\:\mathrm{x}\:=\mathrm{0} \\ $$$$\Rightarrow\ell\:=\:\frac{\mathrm{1}+\sqrt{\mathrm{1}+\mathrm{4cos}\:\mathrm{x}}}{\mathrm{2}}…

tan-x-dx-

Question Number 78575 by TawaTawa last updated on 18/Jan/20 $$\int\:\sqrt{\mathrm{tan}\:\mathrm{x}}\:\:\mathrm{dx} \\ $$ Answered by peter frank last updated on 18/Jan/20 $${u}=\sqrt{\mathrm{tan}\:{x}} \\ $$$${dx}=\frac{\mathrm{2}{udu}}{\mathrm{1}+{u}^{\mathrm{4}} } \\…