Question Number 131558 by liberty last updated on 06/Feb/21
![∫_0 ^1 (dx/( (√(1−x^4 )))) =?](https://www.tinkutara.com/question/Q131558.png)
$$\int_{\mathrm{0}} ^{\mathrm{1}} \frac{\mathrm{dx}}{\:\sqrt{\mathrm{1}−\mathrm{x}^{\mathrm{4}} }}\:=? \\ $$
Answered by Dwaipayan Shikari last updated on 06/Feb/21
![∫_0 ^1 (dx/( (√(1−x^4 )))) x^4 =u =(1/4)∫_0 ^1 u^(−(3/4)) (1−u)^(−(1/2)) du=(1/4).((Γ((1/4))Γ((1/2)))/(Γ((3/4))))=(π^(3/2) /(2(√2)Γ^2 ((3/4))))](https://www.tinkutara.com/question/Q131562.png)
$$\int_{\mathrm{0}} ^{\mathrm{1}} \frac{{dx}}{\:\sqrt{\mathrm{1}−{x}^{\mathrm{4}} }}\:\:\:\:\:\:\:\:\:\:{x}^{\mathrm{4}} ={u} \\ $$$$=\frac{\mathrm{1}}{\mathrm{4}}\int_{\mathrm{0}} ^{\mathrm{1}} {u}^{−\frac{\mathrm{3}}{\mathrm{4}}} \left(\mathrm{1}−{u}\right)^{−\frac{\mathrm{1}}{\mathrm{2}}} {du}=\frac{\mathrm{1}}{\mathrm{4}}.\frac{\Gamma\left(\frac{\mathrm{1}}{\mathrm{4}}\right)\Gamma\left(\frac{\mathrm{1}}{\mathrm{2}}\right)}{\Gamma\left(\frac{\mathrm{3}}{\mathrm{4}}\right)}=\frac{\pi^{\frac{\mathrm{3}}{\mathrm{2}}} }{\mathrm{2}\sqrt{\mathrm{2}}\Gamma^{\mathrm{2}} \left(\frac{\mathrm{3}}{\mathrm{4}}\right)} \\ $$