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Author: Tinku Tara

Use-Residus-theorem-to-prove-that-a-gt-0-n-0-1-n-2-a-2-1-2-pi-ash-pia-1-a-2-and-n-0-1-n-n-2-a-2-1-2-pi-a-th-pia-1-a-2-Assume

Question Number 69236 by ~ À ® @ 237 ~ last updated on 21/Sep/19 $${Use}\:\:{Residus}\:{theorem}\:{to}\:{prove}\:{that}\:\forall\:{a}>\mathrm{0}\:\:\underset{{n}=\mathrm{0}} {\overset{\infty} {\sum}}\:\frac{\mathrm{1}}{\:{n}^{\mathrm{2}} +{a}^{\mathrm{2}} }\:=\:\frac{\mathrm{1}}{\mathrm{2}}\left(\frac{\pi}{{ash}\left(\pi{a}\right)}\:\:\:−\frac{\mathrm{1}}{{a}^{\mathrm{2}} }\right) \\ $$$${and}\:\:\:\:\:\:\underset{{n}=\mathrm{0}} {\overset{\infty} {\sum}}\:\frac{\left(−\mathrm{1}\right)^{{n}} }{{n}^{\mathrm{2}}…

Z-0-2-dx-x-1-

Question Number 134764 by bramlexs22 last updated on 07/Mar/21 $$\:\mathbb{Z}\:=\:\int_{\mathrm{0}} ^{\:\mathrm{2}} \:\frac{\mathrm{dx}}{\:\sqrt{\mid\mathrm{x}−\mathrm{1}\mid}}\:? \\ $$ Answered by EDWIN88 last updated on 07/Mar/21 $$\mathbb{Z}\:=\:\int_{\mathrm{0}} ^{\:\mathrm{2}} \:\frac{\mathrm{dx}}{\:\sqrt{\mid\mathrm{x}−\mathrm{1}\mid}}\:;\:\mathrm{let}\:\mathrm{u}=\mid\mathrm{x}−\mathrm{1}\mid \\…

Prove-that-p-0-1-p-4p-1-pi-argcoth-2-4-2-and-p-0-1-p-4p-3-pi-argcoth-2-4-2-

Question Number 69231 by ~ À ® @ 237 ~ last updated on 21/Sep/19 $${Prove}\:{that}\:\:\underset{{p}=\mathrm{0}} {\overset{\infty} {\sum}}\:\:\frac{\left(−\mathrm{1}\right)^{{p}} }{\mathrm{4}{p}+\mathrm{1}}\:=\:\frac{\pi−{argcoth}\left(\sqrt{\mathrm{2}}\:\right)}{\mathrm{4}\sqrt{\mathrm{2}}}\:\:{and} \\ $$$$\underset{{p}=\mathrm{0}} {\overset{\infty\:} {\sum}}\:\frac{\left(−\mathrm{1}\right)^{{p}} }{\mathrm{4}{p}+\mathrm{3}}\:=\:\frac{\pi+{argcoth}\left(\sqrt{\mathrm{2}}\:\right)}{\mathrm{4}\sqrt{\mathrm{2}}\:}\:\:\: \\ $$…