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Author: Tinku Tara

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Question Number 1988 by Rasheed Soomro last updated on 28/Oct/15 $${x}^{\mathrm{2}} =\:\frac{{f}\left({x}\right)+{f}\left(−{x}\right)}{\mathrm{2}} \\ $$$${f}\left({x}\right)=? \\ $$ Answered by 123456 last updated on 28/Oct/15 $$\mathrm{supossing}\:\mathrm{that}\:{f}\:\mathrm{is}\:\mathrm{poly} \\…

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Question Number 67522 by mathmax by abdo last updated on 28/Aug/19 $${let}\:{z}\:{from}\:{C}−{Z}\:\:\:\:\:{prove}\:{that} \\ $$$$\frac{\pi}{{sin}\left(\pi{z}\right)}\:=\frac{\mathrm{1}}{{z}}\:+\sum_{{n}=\mathrm{1}} ^{\infty} \:\frac{\left(−\mathrm{1}\right)^{{n}} \mathrm{2}{z}}{{z}^{\mathrm{2}} −{n}^{\mathrm{2}} }\:\:{and} \\ $$$$\frac{\pi{cos}\left(\pi{z}\right)}{{sin}\left(\pi{z}\right)}\:=\frac{\mathrm{1}}{{z}}\:+\sum_{{n}=\mathrm{1}} ^{\infty} \:\frac{\mathrm{2}{z}}{{z}^{\mathrm{2}} −{n}^{\mathrm{2}} }…

lets-a-lt-b-and-f-a-b-R-integable-into-a-b-and-continuous-lets-I-a-closed-subset-of-a-b-proof-that-or-give-a-conter-example-I-fdx-0-I-a-b-f-0-

Question Number 1987 by 123456 last updated on 28/Oct/15 $$\mathrm{lets}\:{a}<{b}\:\mathrm{and}\:{f}:\left[{a},{b}\right]\rightarrow\mathbb{R}\:\mathrm{integable}\:\mathrm{into}\:\left[{a},{b}\right]\:\mathrm{and}\:\mathrm{continuous} \\ $$$$\mathrm{lets}\:\mathrm{I}\:\mathrm{a}\:\mathrm{closed}\:\mathrm{subset}\:\mathrm{of}\:\left[{a},{b}\right] \\ $$$$\mathrm{proof}\:\mathrm{that}\:\left(\mathrm{or}\:\mathrm{give}\:\mathrm{a}\:\mathrm{conter}\:\mathrm{example}\right) \\ $$$$\underset{\mathrm{I}} {\int}{fdx}=\mathrm{0}\:\forall\mathrm{I}\subset\left[{a},{b}\right]\Rightarrow{f}=\mathrm{0} \\ $$ Commented by prakash jain last updated…