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Advanced-Calculus-Q-Find-the-value-of-determinant-i-0-1-Ln-2-x-dx-ii-




Question Number 145602 by mnjuly1970 last updated on 06/Jul/21
                   .....Advanced .........Calculus.....     Q::      Find the value of ::                           determinant ((( i ::   ๐›— := โˆซ_0 ^( 1) Ln ( ฮ“ ( 2 + x ) )dx = ?    )),(( ii ::   ฮฉ := ฮฃ_(n=1) ^โˆž (( 1)/( n ( 2n + 3 ))) = ?)))                                               .....m.n.july.1970.....    โ– 
$$ \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:…..\mathrm{Advanced}\:………\mathrm{Calculus}….. \\ $$$$\:\:\:\mathrm{Q}::\:\:\:\:\:\:\mathrm{Find}\:\mathrm{the}\:\mathrm{value}\:\mathrm{of}\::: \\ $$$$ \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\begin{array}{|c|c|}{\:{i}\:::\:\:\:\boldsymbol{\phi}\::=\:\int_{\mathrm{0}} ^{\:\mathrm{1}} \mathrm{Ln}\:\left(\:\Gamma\:\left(\:\mathrm{2}\:+\:{x}\:\right)\:\right){dx}\:=\:?\:\:\:\:}\\{\:{ii}\:::\:\:\:\Omega\::=\:\underset{{n}=\mathrm{1}} {\overset{\infty} {\sum}}\frac{\:\mathrm{1}}{\:{n}\:\left(\:\mathrm{2}{n}\:+\:\mathrm{3}\:\right)}\:=\:?}\\\hline\end{array} \\ $$$$ \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:…..{m}.{n}.{july}.\mathrm{1970}…..\:\:\:\:\blacksquare \\ $$$$ \\ $$
Answered by ajfour last updated on 06/Jul/21
(ii)  S=ฮฃ_(n=1) ^โˆž (1/(n(2n+3)))    ((3S)/2)=ฮฃ_(n=1) ^โˆž ((2n+3โˆ’2n)/(2n(2n+3)))          =ฮฃ_(n=1) ^โˆž ((1/(2n))โˆ’(1/(2n+3)))  ln (1โˆ’x)=โˆ’(x+(x^2 /2)+(x^3 /3)+..)  ฮฃ_(n=1) ^โˆž (1/(2n))=โˆ’(1/2)lim_(xโ†’1)  ln (1โˆ’x)  ln (1+x)โˆ’ln (1โˆ’x)     =2(x+(x^3 /3)+(x^5 /5)+...)  lim_(xโ†’1) [(1/2){ln (1+x)โˆ’ln (1โˆ’x)}    โˆ’xโˆ’(x^3 /3)] =ฮฃ_(n=1) ^โˆž (1/(2n+3))  ((3S)/2)=โˆ’(1/2)lim ln (1โˆ’x)โˆ’  lim_(xโ†’1) [(1/2){ln (1+x)โˆ’ln (1โˆ’x)}                โˆ’xโˆ’(x^3 /3)]    ((3S)/2)= (4/3)โˆ’((ln 2)/2)    S=(8/9)โˆ’((ln 2)/3)
$$\left({ii}\right) \\ $$$${S}=\underset{{n}=\mathrm{1}} {\overset{\infty} {\sum}}\frac{\mathrm{1}}{{n}\left(\mathrm{2}{n}+\mathrm{3}\right)} \\ $$$$\:\:\frac{\mathrm{3}{S}}{\mathrm{2}}=\underset{{n}=\mathrm{1}} {\overset{\infty} {\sum}}\frac{\mathrm{2}{n}+\mathrm{3}โˆ’\mathrm{2}{n}}{\mathrm{2}{n}\left(\mathrm{2}{n}+\mathrm{3}\right)} \\ $$$$\:\:\:\:\:\:\:\:=\underset{{n}=\mathrm{1}} {\overset{\infty} {\sum}}\left(\frac{\mathrm{1}}{\mathrm{2}{n}}โˆ’\frac{\mathrm{1}}{\mathrm{2}{n}+\mathrm{3}}\right) \\ $$$$\mathrm{ln}\:\left(\mathrm{1}โˆ’{x}\right)=โˆ’\left({x}+\frac{{x}^{\mathrm{2}} }{\mathrm{2}}+\frac{{x}^{\mathrm{3}} }{\mathrm{3}}+..\right) \\ $$$$\underset{{n}=\mathrm{1}} {\overset{\infty} {\sum}}\frac{\mathrm{1}}{\mathrm{2}{n}}=โˆ’\frac{\mathrm{1}}{\mathrm{2}}\underset{{x}\rightarrow\mathrm{1}} {\mathrm{lim}}\:\mathrm{ln}\:\left(\mathrm{1}โˆ’{x}\right) \\ $$$$\mathrm{ln}\:\left(\mathrm{1}+{x}\right)โˆ’\mathrm{ln}\:\left(\mathrm{1}โˆ’{x}\right) \\ $$$$\:\:\:=\mathrm{2}\left({x}+\frac{{x}^{\mathrm{3}} }{\mathrm{3}}+\frac{{x}^{\mathrm{5}} }{\mathrm{5}}+…\right) \\ $$$$\underset{{x}\rightarrow\mathrm{1}} {\mathrm{lim}}\left[\frac{\mathrm{1}}{\mathrm{2}}\left\{\mathrm{ln}\:\left(\mathrm{1}+{x}\right)โˆ’\mathrm{ln}\:\left(\mathrm{1}โˆ’{x}\right)\right\}\right. \\ $$$$\left.\:\:โˆ’{x}โˆ’\frac{{x}^{\mathrm{3}} }{\mathrm{3}}\right]\:=\underset{{n}=\mathrm{1}} {\overset{\infty} {\sum}}\frac{\mathrm{1}}{\mathrm{2}{n}+\mathrm{3}} \\ $$$$\frac{\mathrm{3}{S}}{\mathrm{2}}=โˆ’\frac{\mathrm{1}}{\mathrm{2}}\mathrm{lim}\:\mathrm{ln}\:\left(\mathrm{1}โˆ’{x}\right)โˆ’ \\ $$$$\underset{{x}\rightarrow\mathrm{1}} {\mathrm{lim}}\left[\frac{\mathrm{1}}{\mathrm{2}}\left\{\mathrm{ln}\:\left(\mathrm{1}+{x}\right)โˆ’\mathrm{ln}\:\left(\mathrm{1}โˆ’{x}\right)\right\}\right. \\ $$$$\left.\:\:\:\:\:\:\:\:\:\:\:\:\:\:โˆ’{x}โˆ’\frac{{x}^{\mathrm{3}} }{\mathrm{3}}\right] \\ $$$$\:\:\frac{\mathrm{3}{S}}{\mathrm{2}}=\:\frac{\mathrm{4}}{\mathrm{3}}โˆ’\frac{\mathrm{ln}\:\mathrm{2}}{\mathrm{2}} \\ $$$$\:\:{S}=\frac{\mathrm{8}}{\mathrm{9}}โˆ’\frac{\mathrm{ln}\:\mathrm{2}}{\mathrm{3}} \\ $$$$\:\:\:\:\:\:\:\:\:\: \\ $$$$\:\:\: \\ $$
Commented by mnjuly1970 last updated on 06/Jul/21
bravo mr ajfor your work    is admirable...
$${bravo}\:{mr}\:{ajfor}\:{your}\:{work}\: \\ $$$$\:{is}\:{admirable}… \\ $$
Answered by Olaf_Thorendsen last updated on 06/Jul/21
ฮฉ = ฮฃ_(n=1) ^โˆž (1/(n(2n+3)))= (1/2)ฮฃ_(n=0) ^โˆž (1/((n+1)(n+(5/2))))  ฮฉ = (1/2).((ฯˆ((5/2))โˆ’ฯˆ(1))/((5/2)โˆ’1)) = (1/3)(ฯˆ((5/2))+ฮณ)  ฯˆ((5/2)) = ฯˆ(1+(3/2)) = ฯˆ((3/2))+(1/(3/2)) = ฯˆ((3/2))+(2/3)  ฯˆ((3/2)) = ฯˆ(1+(1/2)) = ฯˆ((1/2))+(1/(1/2)) = โˆ’2ln(2)โˆ’ฮณ+2     ฮฉ = (1/3)(โˆ’2ln(2)โˆ’ฮณ+2+(2/3)+ฮณ) = (2/3)((4/3)โˆ’ln(2))
$$\Omega\:=\:\underset{{n}=\mathrm{1}} {\overset{\infty} {\sum}}\frac{\mathrm{1}}{{n}\left(\mathrm{2}{n}+\mathrm{3}\right)}=\:\frac{\mathrm{1}}{\mathrm{2}}\underset{{n}=\mathrm{0}} {\overset{\infty} {\sum}}\frac{\mathrm{1}}{\left({n}+\mathrm{1}\right)\left({n}+\frac{\mathrm{5}}{\mathrm{2}}\right)} \\ $$$$\Omega\:=\:\frac{\mathrm{1}}{\mathrm{2}}.\frac{\psi\left(\frac{\mathrm{5}}{\mathrm{2}}\right)โˆ’\psi\left(\mathrm{1}\right)}{\frac{\mathrm{5}}{\mathrm{2}}โˆ’\mathrm{1}}\:=\:\frac{\mathrm{1}}{\mathrm{3}}\left(\psi\left(\frac{\mathrm{5}}{\mathrm{2}}\right)+\gamma\right) \\ $$$$\psi\left(\frac{\mathrm{5}}{\mathrm{2}}\right)\:=\:\psi\left(\mathrm{1}+\frac{\mathrm{3}}{\mathrm{2}}\right)\:=\:\psi\left(\frac{\mathrm{3}}{\mathrm{2}}\right)+\frac{\mathrm{1}}{\mathrm{3}/\mathrm{2}}\:=\:\psi\left(\frac{\mathrm{3}}{\mathrm{2}}\right)+\frac{\mathrm{2}}{\mathrm{3}} \\ $$$$\psi\left(\frac{\mathrm{3}}{\mathrm{2}}\right)\:=\:\psi\left(\mathrm{1}+\frac{\mathrm{1}}{\mathrm{2}}\right)\:=\:\psi\left(\frac{\mathrm{1}}{\mathrm{2}}\right)+\frac{\mathrm{1}}{\mathrm{1}/\mathrm{2}}\:=\:โˆ’\mathrm{2ln}\left(\mathrm{2}\right)โˆ’\gamma+\mathrm{2} \\ $$$$\: \\ $$$$\Omega\:=\:\frac{\mathrm{1}}{\mathrm{3}}\left(โˆ’\mathrm{2ln}\left(\mathrm{2}\right)โˆ’\gamma+\mathrm{2}+\frac{\mathrm{2}}{\mathrm{3}}+\gamma\right)\:=\:\frac{\mathrm{2}}{\mathrm{3}}\left(\frac{\mathrm{4}}{\mathrm{3}}โˆ’\mathrm{ln}\left(\mathrm{2}\right)\right) \\ $$
Commented by mnjuly1970 last updated on 06/Jul/21
grateful mr olaf   very nice as always..mercey
$${grateful}\:{mr}\:{olaf}\: \\ $$$${very}\:{nice}\:{as}\:{always}..{mercey} \\ $$
Answered by qaz last updated on 06/Jul/21
ฮ“(x)ฮ“(1โˆ’x)=(ฯ€/(sin ฯ€x))
$$\Gamma\left(\mathrm{x}\right)\Gamma\left(\mathrm{1}โˆ’\mathrm{x}\right)=\frac{\pi}{\mathrm{sin}\:\pi\mathrm{x}} \\ $$
Answered by Kamel last updated on 06/Jul/21
i) use t=1โˆ’x and: ฮ“(t)ฮ“(1โˆ’t)=(ฯ€/(sin(ฯ€t)))  ii.. ฮฉ=ฮฃ_(n=1) ^(+โˆž) (1/(n(2n+3)))=(2/3)ฮฃ_(n=1) ^(+โˆž) ((1/(2n))โˆ’(1/(2n+3)))=(2/3)(ฮฃ_(n=1) ^(+โˆž) ((1/(2n))โˆ’(1/(2n+1)))+ฮฃ_(n=1) ^(+โˆž) ((1/(2n+1))โˆ’(1/(2(n+1)+1))))             =(2/3)(ฮฃ_(n=1) ^(+โˆž) (((โˆ’1)^n )/n)+1+(1/3))=(2/3)((4/3)โˆ’Ln(2))=(8/9)โˆ’((2Ln(2))/3)
$$\left.{i}\right)\:{use}\:{t}=\mathrm{1}โˆ’{x}\:{and}:\:\Gamma\left({t}\right)\Gamma\left(\mathrm{1}โˆ’{t}\right)=\frac{\pi}{{sin}\left(\pi{t}\right)} \\ $$$${ii}..\:\Omega=\underset{{n}=\mathrm{1}} {\overset{+\infty} {\sum}}\frac{\mathrm{1}}{{n}\left(\mathrm{2}{n}+\mathrm{3}\right)}=\frac{\mathrm{2}}{\mathrm{3}}\underset{{n}=\mathrm{1}} {\overset{+\infty} {\sum}}\left(\frac{\mathrm{1}}{\mathrm{2}{n}}โˆ’\frac{\mathrm{1}}{\mathrm{2}{n}+\mathrm{3}}\right)=\frac{\mathrm{2}}{\mathrm{3}}\left(\underset{{n}=\mathrm{1}} {\overset{+\infty} {\sum}}\left(\frac{\mathrm{1}}{\mathrm{2}{n}}โˆ’\frac{\mathrm{1}}{\mathrm{2}{n}+\mathrm{1}}\right)+\underset{{n}=\mathrm{1}} {\overset{+\infty} {\sum}}\left(\frac{\mathrm{1}}{\mathrm{2}{n}+\mathrm{1}}โˆ’\frac{\mathrm{1}}{\mathrm{2}\left({n}+\mathrm{1}\right)+\mathrm{1}}\right)\right) \\ $$$$\:\:\:\:\:\:\:\:\:\:\:=\frac{\mathrm{2}}{\mathrm{3}}\left(\underset{{n}=\mathrm{1}} {\overset{+\infty} {\sum}}\frac{\left(โˆ’\mathrm{1}\right)^{{n}} }{{n}}+\mathrm{1}+\frac{\mathrm{1}}{\mathrm{3}}\right)=\frac{\mathrm{2}}{\mathrm{3}}\left(\frac{\mathrm{4}}{\mathrm{3}}โˆ’{Ln}\left(\mathrm{2}\right)\right)=\frac{\mathrm{8}}{\mathrm{9}}โˆ’\frac{\mathrm{2}{Ln}\left(\mathrm{2}\right)}{\mathrm{3}} \\ $$
Commented by mnjuly1970 last updated on 06/Jul/21
tashakor mr kamel
$${tashakor}\:{mr}\:{kamel} \\ $$
Answered by ArielVyny last updated on 06/Jul/21
โˆ…=โˆซ_0 ^1 ln(ฮ“(2+x))dx  =โˆซ_0 ^1 ln((x+1)!)dx  x+1=tโ†’dt=dx  โˆ…=โˆซ_1 ^2 ln(t!)dt=โˆซ_1 ^2 ln[((t/e))^t (โˆš(2ฯ€t))]  โˆซ_1 ^2 ln((t/e))^t +โˆซ_1 ^2 ln((โˆš(2ฯ€t)))dt  โˆซ_1 ^2 ln(e^(tln((t/e))) )+โˆซ_1 ^2 ln((โˆš(2ฯ€)))dt+(1/2)โˆซ_1 ^2 ln(t)dt  โˆซ_1 ^2 tln((t/e))+ln((โˆš(2ฯ€)))+(1/2)[xln(x)โˆ’x]_1 ^2   โˆซ_1 ^2 tln(t)โˆ’โˆซ_1 ^2 tdt+ln((โˆš(2ฯ€)))+(1/2)(2ln(2)+1)  โˆซ_1 ^2 tln(t)dtโˆ’(3/2)+(1/2)ln(2ฯ€)+((2ln2)/2)+(1/2)  โˆซ_1 ^2 tln(t)dt  du=ln(t)              v=t  u=tln(t)โˆ’t         dv=1  โˆซ_1 ^2 tln(t)=[t^2 ln(t)โˆ’t]โˆ’โˆซtlntdt+โˆซtdt  2โˆซ_1 ^2 tln(t)dt=[t^2 ln(t)โˆ’t+(1/2)t^2 ]_1 ^2 =4ln(2)โˆ’2+(1/2)4+1โˆ’(1/2)  โˆซ_1 ^2 tln(t)dt=2ln(2)โˆ’1+1+(1/2)โˆ’(1/4)                         =2ln(2)+(1/4)  โˆ…=2ln(2)+(1/4)โˆ’(3/2)+((ln(2ฯ€))/2)+((2ln(2))/2)+(1/2)  โˆ…=2ln(2)+(1/4)โˆ’1+((ln(8ฯ€))/2)  โˆ…=โˆ’(3/4)+((2ln(4))/2)+((ln(8ฯ€))/2)  โˆ…=โˆ’(3/4)+(1/2)ln(8^3 ฯ€)
$$\emptyset=\int_{\mathrm{0}} ^{\mathrm{1}} {ln}\left(\Gamma\left(\mathrm{2}+{x}\right)\right){dx} \\ $$$$=\int_{\mathrm{0}} ^{\mathrm{1}} {ln}\left(\left({x}+\mathrm{1}\right)!\right){dx} \\ $$$${x}+\mathrm{1}={t}\rightarrow{dt}={dx} \\ $$$$\emptyset=\int_{\mathrm{1}} ^{\mathrm{2}} {ln}\left({t}!\right){dt}=\int_{\mathrm{1}} ^{\mathrm{2}} {ln}\left[\left(\frac{{t}}{{e}}\right)^{{t}} \sqrt{\mathrm{2}\pi{t}}\right] \\ $$$$\int_{\mathrm{1}} ^{\mathrm{2}} {ln}\left(\frac{{t}}{{e}}\right)^{{t}} +\int_{\mathrm{1}} ^{\mathrm{2}} {ln}\left(\sqrt{\mathrm{2}\pi{t}}\right){dt} \\ $$$$\int_{\mathrm{1}} ^{\mathrm{2}} {ln}\left({e}^{{tln}\left(\frac{{t}}{{e}}\right)} \right)+\int_{\mathrm{1}} ^{\mathrm{2}} {ln}\left(\sqrt{\mathrm{2}\pi}\right){dt}+\frac{\mathrm{1}}{\mathrm{2}}\int_{\mathrm{1}} ^{\mathrm{2}} {ln}\left({t}\right){dt} \\ $$$$\int_{\mathrm{1}} ^{\mathrm{2}} {tln}\left(\frac{{t}}{{e}}\right)+{ln}\left(\sqrt{\mathrm{2}\pi}\right)+\frac{\mathrm{1}}{\mathrm{2}}\left[{xln}\left({x}\right)โˆ’{x}\right]_{\mathrm{1}} ^{\mathrm{2}} \\ $$$$\int_{\mathrm{1}} ^{\mathrm{2}} {tln}\left({t}\right)โˆ’\int_{\mathrm{1}} ^{\mathrm{2}} {tdt}+{ln}\left(\sqrt{\mathrm{2}\pi}\right)+\frac{\mathrm{1}}{\mathrm{2}}\left(\mathrm{2}{ln}\left(\mathrm{2}\right)+\mathrm{1}\right) \\ $$$$\int_{\mathrm{1}} ^{\mathrm{2}} {tln}\left({t}\right){dt}โˆ’\frac{\mathrm{3}}{\mathrm{2}}+\frac{\mathrm{1}}{\mathrm{2}}{ln}\left(\mathrm{2}\pi\right)+\frac{\mathrm{2}{ln}\mathrm{2}}{\mathrm{2}}+\frac{\mathrm{1}}{\mathrm{2}} \\ $$$$\int_{\mathrm{1}} ^{\mathrm{2}} {tln}\left({t}\right){dt} \\ $$$${du}={ln}\left({t}\right)\:\:\:\:\:\:\:\:\:\:\:\:\:\:{v}={t} \\ $$$${u}={tln}\left({t}\right)โˆ’{t}\:\:\:\:\:\:\:\:\:{dv}=\mathrm{1} \\ $$$$\int_{\mathrm{1}} ^{\mathrm{2}} {tln}\left({t}\right)=\left[{t}^{\mathrm{2}} {ln}\left({t}\right)โˆ’{t}\right]โˆ’\int{tlntdt}+\int{tdt} \\ $$$$\mathrm{2}\int_{\mathrm{1}} ^{\mathrm{2}} {tln}\left({t}\right){dt}=\left[{t}^{\mathrm{2}} {ln}\left({t}\right)โˆ’{t}+\frac{\mathrm{1}}{\mathrm{2}}{t}^{\mathrm{2}} \right]_{\mathrm{1}} ^{\mathrm{2}} =\mathrm{4}{ln}\left(\mathrm{2}\right)โˆ’\mathrm{2}+\frac{\mathrm{1}}{\mathrm{2}}\mathrm{4}+\mathrm{1}โˆ’\frac{\mathrm{1}}{\mathrm{2}} \\ $$$$\int_{\mathrm{1}} ^{\mathrm{2}} {tln}\left({t}\right){dt}=\mathrm{2}{ln}\left(\mathrm{2}\right)โˆ’\mathrm{1}+\mathrm{1}+\frac{\mathrm{1}}{\mathrm{2}}โˆ’\frac{\mathrm{1}}{\mathrm{4}} \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:=\mathrm{2}{ln}\left(\mathrm{2}\right)+\frac{\mathrm{1}}{\mathrm{4}} \\ $$$$\emptyset=\mathrm{2}{ln}\left(\mathrm{2}\right)+\frac{\mathrm{1}}{\mathrm{4}}โˆ’\frac{\mathrm{3}}{\mathrm{2}}+\frac{{ln}\left(\mathrm{2}\pi\right)}{\mathrm{2}}+\frac{\mathrm{2}{ln}\left(\mathrm{2}\right)}{\mathrm{2}}+\frac{\mathrm{1}}{\mathrm{2}} \\ $$$$\emptyset=\mathrm{2}{ln}\left(\mathrm{2}\right)+\frac{\mathrm{1}}{\mathrm{4}}โˆ’\mathrm{1}+\frac{{ln}\left(\mathrm{8}\pi\right)}{\mathrm{2}} \\ $$$$\emptyset=โˆ’\frac{\mathrm{3}}{\mathrm{4}}+\frac{\mathrm{2}{ln}\left(\mathrm{4}\right)}{\mathrm{2}}+\frac{{ln}\left(\mathrm{8}\pi\right)}{\mathrm{2}} \\ $$$$\emptyset=โˆ’\frac{\mathrm{3}}{\mathrm{4}}+\frac{\mathrm{1}}{\mathrm{2}}{ln}\left(\mathrm{8}^{\mathrm{3}} \pi\right) \\ $$
Commented by mathmax by abdo last updated on 06/Jul/21
t!โˆผ((t/e))^t (โˆš(2ฯ€t))is valable pour t assez grand(tโ†’โˆž)
$$\mathrm{t}!\sim\left(\frac{\mathrm{t}}{\mathrm{e}}\right)^{\mathrm{t}} \sqrt{\mathrm{2}\pi\mathrm{t}}\mathrm{is}\:\mathrm{valable}\:\mathrm{pour}\:\mathrm{t}\:\mathrm{assez}\:\mathrm{grand}\left(\mathrm{t}\rightarrow\infty\right) \\ $$

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