Menu Close

Category: Algebra

S-x-2x-2-nx-n-

Question Number 153847 by mathdanisur last updated on 11/Sep/21 $$\boldsymbol{\mathrm{S}}\:=\:\mathrm{x}\:+\:\mathrm{2x}^{\mathrm{2}} \:+\:…\:+\:\mathrm{nx}^{\boldsymbol{\mathrm{n}}} \\ $$$$ \\ $$ Answered by liberty last updated on 11/Sep/21 $$\:{S}={x}+\mathrm{2}{x}^{\mathrm{2}} +\mathrm{3}{x}^{\mathrm{3}} +\mathrm{4}{x}^{\mathrm{4}}…

Question-153839

Question Number 153839 by liberty last updated on 11/Sep/21 Commented by mathdanisur last updated on 11/Sep/21 $$\mathrm{x}\left(\mathrm{1}\:+\:\frac{\mathrm{1}}{\mathrm{1}+\mathrm{2}}\:+\:\frac{\mathrm{1}}{\mathrm{1}+\mathrm{2}+\mathrm{3}}\:+\:…\:+\:\frac{\mathrm{1}}{\mathrm{1}+\mathrm{2}+…+\mathrm{4041}}\right)\:=\:\mathrm{4041} \\ $$$$\blacktriangle\:\boldsymbol{\mathrm{A}}\:=\:\mathrm{1}\:+\:\frac{\mathrm{1}}{\mathrm{1}+\mathrm{2}}\:+\:\frac{\mathrm{1}}{\mathrm{1}+\mathrm{2}+\mathrm{3}}\:+\:…\:+\:\frac{\mathrm{1}}{\mathrm{1}+\mathrm{2}+…+\boldsymbol{\mathrm{n}}}\:=\:\frac{\mathrm{2}\boldsymbol{\mathrm{n}}}{\boldsymbol{\mathrm{n}}\:+\:\mathrm{1}} \\ $$$$\boldsymbol{\mathrm{n}}\:=\:\mathrm{4041}\:\Rightarrow\:\boldsymbol{\mathrm{A}}\:=\:\frac{\mathrm{2}\:\centerdot\:\mathrm{4041}}{\mathrm{4041}\:+\:\mathrm{1}}\:=\:\frac{\mathrm{2}\:\centerdot\:\mathrm{4041}}{\mathrm{2}\:\centerdot\:\mathrm{2021}}\:=\:\frac{\mathrm{4041}}{\mathrm{2021}} \\ $$$$\Rightarrow\:\boldsymbol{\mathrm{x}}\:\centerdot\:\frac{\mathrm{4041}}{\mathrm{2021}}\:=\:\mathrm{4041}\:\Rightarrow\:\boldsymbol{\mathrm{x}}\:=\:\mathrm{2021}\:\blacktriangle \\ $$…

L-x-6-pi-2-Li-2-x-1-2-log-x-log-1-x-Find-0-1-L-x-Li-2-x-dx-

Question Number 153829 by mathdanisur last updated on 10/Sep/21 $$\mathrm{L}\left(\mathrm{x}\right)\:=\:\frac{\mathrm{6}}{\pi^{\mathrm{2}} }\left(\mathrm{Li}_{\mathrm{2}} \left(\mathrm{x}\right)\:+\:\frac{\mathrm{1}}{\mathrm{2}}\:\mathrm{log}\left(\mathrm{x}\right)\mathrm{log}\left(\mathrm{1}-\mathrm{x}\right)\right. \\ $$$$\mathrm{Find}:\:\:\boldsymbol{\Omega}\:=\underset{\:\mathrm{0}} {\overset{\:\mathrm{1}} {\int}}\:\mathrm{L}\left(\mathrm{x}\right)\centerdot\mathrm{Li}_{\mathrm{2}} \left(\mathrm{x}\right)\:\mathrm{dx} \\ $$ Terms of Service Privacy Policy Contact:…

If-0-lt-a-b-lt-1-then-a-b-a-b-a-b-1-xyz-1-xyz-3-dxdydz-a-b-1-x-3-1-x-3-dx-3-

Question Number 153808 by mathdanisur last updated on 10/Sep/21 $$\mathrm{If}\:\:\mathrm{0}<\mathrm{a}\leqslant\mathrm{b}<\mathrm{1}\:\:\mathrm{then}: \\ $$$$\underset{\:\boldsymbol{\mathrm{a}}} {\overset{\:\boldsymbol{\mathrm{b}}} {\int}}\underset{\:\boldsymbol{\mathrm{a}}} {\overset{\:\boldsymbol{\mathrm{b}}} {\int}}\underset{\boldsymbol{\mathrm{a}}} {\overset{\:\boldsymbol{\mathrm{b}}} {\int}}\left(\frac{\mathrm{1}\:-\:\mathrm{xyz}}{\mathrm{1}\:+\:\mathrm{xyz}}\right)^{\mathrm{3}} \mathrm{dxdydz}\:\geqslant\:\left(\underset{\boldsymbol{\mathrm{a}}} {\overset{\:\boldsymbol{\mathrm{b}}} {\int}}\frac{\mathrm{1}\:-\:\mathrm{x}^{\mathrm{3}} }{\mathrm{1}\:+\:\mathrm{x}^{\mathrm{3}} }\:\mathrm{dx}\right)^{\mathrm{3}} \\ $$…

If-1-x-n-C-0-C-1-x-C-2-x-2-C-3-x-3-C-n-x-n-Prove-that-0-i-lt-j-n-i-j-C-i-C-j-n-2-2n-1-1-2-2n-C-n-

Question Number 22739 by Tinkutara last updated on 22/Oct/17 $${If}\:\left(\mathrm{1}\:+\:{x}\right)^{{n}} \:=\:{C}_{\mathrm{0}} \:+\:{C}_{\mathrm{1}} {x}\:+\:{C}_{\mathrm{2}} {x}^{\mathrm{2}} \:+\:{C}_{\mathrm{3}} {x}^{\mathrm{3}} \\ $$$$+\:…\:+\:{C}_{{n}} {x}^{{n}} , \\ $$$${Prove}\:{that}\:\underset{\mathrm{0}\leqslant{i}<{j}\leqslant{n}} {\Sigma\Sigma}\left({i}\:+\:{j}\right){C}_{{i}} {C}_{{j}} \:=…