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Category: Limits

Question-157942

Question Number 157942 by mathlove last updated on 30/Oct/21 Commented by cortano last updated on 30/Oct/21 $$\left(\mathrm{1}\right){x}+\mathrm{2}{x}+\mathrm{3}{x}+…+{nx}=\frac{{n}}{\mathrm{2}}\left({nx}+{x}\right) \\ $$$$\left(\mathrm{2}\right)\underset{{x}\rightarrow\mathrm{0}} {\mathrm{lim}}\:\frac{\left(\mathrm{1}+\frac{{x}}{\mathrm{2}}\right)\left(\mathrm{1}+\frac{\mathrm{2}{x}}{\mathrm{2}}\right)\left(\mathrm{1}+\frac{\mathrm{3}{x}}{\mathrm{2}}\right)…\left(\mathrm{1}+\frac{{nx}}{\mathrm{2}}\right)−\mathrm{1}}{\frac{{n}}{\mathrm{2}}\left({nx}+{x}\right)} \\ $$$${L}=\frac{\mathrm{2}}{{n}\left({n}+\mathrm{1}\right)}.\underset{{x}\rightarrow\mathrm{0}} {\mathrm{lim}}\frac{\left(\frac{\mathrm{1}}{\mathrm{2}}+\frac{\mathrm{2}}{\mathrm{2}}+\frac{\mathrm{3}}{\mathrm{2}}+…+\frac{{n}}{\mathrm{2}}\right){x}}{{x}} \\ $$$${L}=\frac{\mathrm{2}}{{n}\left({n}+\mathrm{1}\right)}.\frac{\mathrm{1}}{\mathrm{2}}\left(\mathrm{1}+\mathrm{2}+\mathrm{3}+…+{n}\right)…

i-1-5-1-2-i-3-1-2-i-2-

Question Number 92340 by jagoll last updated on 06/May/20 $$\underset{\mathrm{i}\:=\:\mathrm{1}} {\overset{\infty} {\prod}}\:\frac{\mathrm{5}^{\left(\frac{\mathrm{1}}{\mathrm{2}}\right)^{\mathrm{i}} } +\mathrm{3}^{\left(\frac{\mathrm{1}}{\mathrm{2}}\right)^{\mathrm{i}} } }{\mathrm{2}}\:=\: \\ $$ Commented by john santu last updated on…

lim-x-1-1-x-ln-x-

Question Number 92291 by jagoll last updated on 06/May/20 $$ \\ $$$$\underset{{x}\rightarrow\mathrm{1}^{−} } {\mathrm{lim}}\:\left(\mathrm{1}−\mathrm{x}\right)^{\mathrm{ln}\:\mathrm{x}} \:=?\: \\ $$ Commented by abdomathmax last updated on 06/May/20 $${let}\:{f}\left({x}\right)=\left(\mathrm{1}−{x}\right)^{{lnx}}…

by-using-fourier-serie-find-the-value-of-n-0-1-2n-1-2-

Question Number 26751 by abdo imad last updated on 28/Dec/17 $${by}\:{using}\:{fourier}\:{serie}\:{find}\:{the}\:{value}\:{of}\:\sum_{{n}=\mathrm{0}} ^{\propto} \:\frac{\mathrm{1}}{\left(\mathrm{2}{n}+\mathrm{1}\right)^{\mathrm{2}} } \\ $$ Commented by abdo imad last updated on 30/Dec/17 $${we}\:{know}\:{that}\:/{x}/=\:\frac{\pi}{\mathrm{2}}\:−\frac{\mathrm{4}}{\pi}\:\sum_{{p}=\mathrm{0}}…