Question and Answers Forum

All Questions      Topic List

Integration Questions

Previous in All Question      Next in All Question      

Previous in Integration      Next in Integration      

Question Number 161966 by amin96 last updated on 24/Dec/21

∫x^2 7^x^2  dx=?

$$\int\boldsymbol{\mathrm{x}}^{\mathrm{2}} \mathrm{7}^{\boldsymbol{\mathrm{x}}^{\mathrm{2}} } \boldsymbol{\mathrm{dx}}=? \\ $$

Answered by Ar Brandon last updated on 25/Dec/21

I=∫x^2 7^x^2  dx=∫x^2 e^(x^2 log7) dx=Σ_(n=0) ^∞ ∫x^2 (((x^2 log7)^n )/(n!))dx     =Σ_(n=0) ^∞ ((log^n 7)/(n!(2n+3)))x^(2n+3) =(x^3 /2)Σ_(n=0) ^∞ (((1)_n log^n 7)/(n!(n+(3/2))))x^(2n)      =(x^3 /2)Σ_(n=0) ^∞ (((1)_n Γ(n+(3/2)))/(n!Γ(n+(5/2))))(x^2 log7)^n      =(x^3 /3)Σ_(n=0) ^∞ (((1)_n ((3/2))_n )/(n!((5/2))_n ))(x^2 log7)^n      =(x^3 /3) _2 F_1 (1, (3/2); (5/2); x^2 log7)

$${I}=\int{x}^{\mathrm{2}} \mathrm{7}^{{x}^{\mathrm{2}} } {dx}=\int{x}^{\mathrm{2}} {e}^{{x}^{\mathrm{2}} {log}\mathrm{7}} {dx}=\underset{{n}=\mathrm{0}} {\overset{\infty} {\sum}}\int{x}^{\mathrm{2}} \frac{\left({x}^{\mathrm{2}} {log}\mathrm{7}\right)^{{n}} }{{n}!}{dx} \\ $$$$\:\:\:=\underset{{n}=\mathrm{0}} {\overset{\infty} {\sum}}\frac{{log}^{{n}} \mathrm{7}}{{n}!\left(\mathrm{2}{n}+\mathrm{3}\right)}{x}^{\mathrm{2}{n}+\mathrm{3}} =\frac{{x}^{\mathrm{3}} }{\mathrm{2}}\underset{{n}=\mathrm{0}} {\overset{\infty} {\sum}}\frac{\left(\mathrm{1}\right)_{{n}} {log}^{{n}} \mathrm{7}}{{n}!\left({n}+\frac{\mathrm{3}}{\mathrm{2}}\right)}{x}^{\mathrm{2}{n}} \\ $$$$\:\:\:=\frac{{x}^{\mathrm{3}} }{\mathrm{2}}\underset{{n}=\mathrm{0}} {\overset{\infty} {\sum}}\frac{\left(\mathrm{1}\right)_{{n}} \Gamma\left({n}+\frac{\mathrm{3}}{\mathrm{2}}\right)}{{n}!\Gamma\left({n}+\frac{\mathrm{5}}{\mathrm{2}}\right)}\left({x}^{\mathrm{2}} {log}\mathrm{7}\right)^{{n}} \\ $$$$\:\:\:=\frac{{x}^{\mathrm{3}} }{\mathrm{3}}\underset{{n}=\mathrm{0}} {\overset{\infty} {\sum}}\frac{\left(\mathrm{1}\right)_{{n}} \left(\frac{\mathrm{3}}{\mathrm{2}}\right)_{{n}} }{{n}!\left(\frac{\mathrm{5}}{\mathrm{2}}\right)_{{n}} }\left({x}^{\mathrm{2}} {log}\mathrm{7}\right)^{{n}} \\ $$$$\:\:\:=\frac{{x}^{\mathrm{3}} }{\mathrm{3}}\underset{\mathrm{2}} {\:}{F}_{\mathrm{1}} \left(\mathrm{1},\:\frac{\mathrm{3}}{\mathrm{2}};\:\frac{\mathrm{5}}{\mathrm{2}};\:{x}^{\mathrm{2}} {log}\mathrm{7}\right) \\ $$

Commented by amin96 last updated on 25/Dec/21

what is F_1 ??

$${what}\:{is}\:{F}_{\mathrm{1}} ?? \\ $$

Terms of Service

Privacy Policy

Contact: info@tinkutara.com