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Category: Integration

Nice-Calculus-if-n-0-1-x-n-1-x-dx-then-n-1-1-n-1-n-n-

Question Number 144231 by mnjuly1970 last updated on 23/Jun/21 $$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:…..{Nice}\:…{Calculus} \\ $$$$\:\:\:\:\:\:{if}\:\:::\:\: \\ $$$$\:\:\:\:\:\:\:\varphi\:\left(\:{n}\:\right)\::=\:\int_{\mathrm{0}} ^{\:\mathrm{1}} \frac{{x}^{\:{n}} }{\mathrm{1}\:+\:{x}}\:{dx} \\ $$$$\:\:\:\:\:{then}\:\:::\:\:\:\underset{{n}=\mathrm{1}} {\overset{\:\infty} {\sum}}\frac{\left(−\mathrm{1}\right)^{{n}−\mathrm{1}} \:\varphi\:\left({n}\:\right)}{{n}}\:=? \\ $$$$\:\:\:\:\:\:\:…….. \\…

Question-144168

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