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Question-177975

Question Number 177975 by aurpeyz last updated on 11/Oct/22 Answered by mr W last updated on 11/Oct/22 $$\angle{ACB}={x}/\mathrm{2} \\ $$$$\angle{BAC}={y} \\ $$$$\angle{B}=\mathrm{180}−{x}/\mathrm{2}−{y} \\ $$$$\angle{ADC}=\mathrm{180}−\angle{B}={x}/\mathrm{2}+{y} \\…

Question-112366

Question Number 112366 by mathdave last updated on 07/Sep/20 Answered by mathmax by abdo last updated on 07/Sep/20 $$\mathrm{let}\:\mathrm{S}_{\mathrm{n}} =\mathrm{n}\:\sum_{\mathrm{k}=\mathrm{1}} ^{\mathrm{n}−\mathrm{1}} \:\frac{\mathrm{ln}\left(\mathrm{k}+\mathrm{n}\right)−\mathrm{ln}\left(\mathrm{n}\right)}{\mathrm{n}^{\mathrm{2}} \:+\mathrm{k}^{\mathrm{2}} }\:\Rightarrow \\…

prove-that-0-tanhx-x-3-sech-2-x-x-2-dx-7-pi-2-3-where-3-apery-s-constant-

Question Number 112369 by mathdave last updated on 07/Sep/20 $${prove}\:{that}\: \\ $$$$\int_{\mathrm{0}} ^{\infty} \left(\frac{\mathrm{tanh}{x}}{{x}^{\mathrm{3}} }−\frac{\mathrm{sech}^{\mathrm{2}} {x}}{{x}^{\mathrm{2}} }\right){dx}=\frac{\mathrm{7}}{\pi^{\mathrm{2}} }\zeta\left(\mathrm{3}\right) \\ $$$${where}\:\zeta\left(\mathrm{3}\right)={apery}'{s}\:{constant} \\ $$ Terms of Service…

1-Let-z-3-4i-3-4i-where-square-root-is-taken-with-positive-real-part-Then-Re-z-is-a-3-b-4-c-2-d-1-2-Suppose-a-b-c-are-in-AP-and-a-2-b-2-c-2-are-in-GP-If

Question Number 112364 by john santu last updated on 07/Sep/20 $$\left(\mathrm{1}\right)\:{Let}\:{z}\:=\:\sqrt{\mathrm{3}+\mathrm{4}{i}}\:+\:\sqrt{−\mathrm{3}−\mathrm{4}{i}}\:,\:{where} \\ $$$${square}\:{root}\:{is}\:{taken}\:{with}\:{positive}\: \\ $$$${real}\:{part}.\:{Then}\:{Re}\left({z}\right)\:{is}\:\_ \\ $$$$\left({a}\right)\mathrm{3}\:\:\:\:\:\left({b}\right)\:\mathrm{4}\:\:\:\:\:\left({c}\right)\:\mathrm{2}\:\:\:\:\:\left({d}\right)\:\mathrm{1} \\ $$$$\left(\mathrm{2}\right){Suppose}\:{a},{b},{c}\:{are}\:{in}\:{AP}\:{and}\:{a}^{\mathrm{2}} ,{b}^{\mathrm{2}} ,{c}^{\mathrm{2}} \\ $$$${are}\:{in}\:{GP}.\:{If}\:{a}<{b}<{c}\:{and}\:{a}+{b}+{c}=\frac{\mathrm{3}}{\mathrm{2}}, \\ $$$${then}\:{a}\:=\:\_…

Question-177884

Question Number 177884 by DAVONG last updated on 10/Oct/22 Answered by mr W last updated on 10/Oct/22 $$\mathrm{6}\:{black}\:{and}\:{n}\:{red}\:{balls}\:{in}\:{bag}. \\ $$$${to}\:{take}\:\mathrm{3}\:{balls}\:{there}\:{are}\:{totally} \\ $$$${C}_{\mathrm{3}} ^{{n}+\mathrm{6}} \:{ways}. \\…