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Category: Integration

hi-guyz-let-s-try-this-I-0-1-sin-2-x-cos-3-x-dx-

Question Number 135495 by greg_ed last updated on 13/Mar/21 $$\boldsymbol{\mathrm{hi}},\:\boldsymbol{\mathrm{guyz}}\:! \\ $$$$\boldsymbol{\mathrm{let}}'\boldsymbol{\mathrm{s}}\:\boldsymbol{\mathrm{try}}\:\boldsymbol{\mathrm{this}}\::\:\boldsymbol{\mathrm{I}}=\int_{\mathrm{0}} ^{\:\mathrm{1}} \frac{\boldsymbol{{sin}}^{\mathrm{2}} \boldsymbol{{x}}}{\boldsymbol{{cos}}^{\mathrm{3}} \boldsymbol{{x}}}\boldsymbol{{dx}}. \\ $$ Answered by mathmax by abdo last updated…

for-f-x-dx-F-x-c-and-sgn-x-x-x-x-x-x-0-let-sgn-x-0-for-x-0-does-sgn-f-x-f-x-dx-sgn-f-x-f-x-dx-sgn-f-x-is-just-a-constant-1-or-0-

Question Number 4344 by Filup last updated on 12/Jan/16 $$\mathrm{for}\:\int{f}\left({x}\right){dx}={F}\left({x}\right)+{c} \\ $$$$\mathrm{and}\:{sgn}\left({x}\right)=\frac{{x}}{\mid{x}\mid}=\frac{\mid{x}\mid}{{x}}\:\:\:\forall{x}\neq\mathrm{0} \\ $$$$\:\:\:\:\:\:\:\:\:\:\mathrm{let}\:\mathrm{sgn}\left({x}\right)=\mathrm{0}\:\mathrm{for}\:{x}=\mathrm{0} \\ $$$$ \\ $$$$\mathrm{does}\: \\ $$$$\int{sgn}\left({f}\left({x}\right)\right){f}\left({x}\right){dx}={sgn}\left({f}\left({x}\right)\right)\int{f}\left({x}\right){dx} \\ $$$$\because{sgn}\left({f}\left({x}\right)\right)\:\mathrm{is}\:\mathrm{just}\:\mathrm{a}\:\mathrm{constant}\:\pm\mathrm{1}\:\mathrm{or}\:\mathrm{0}. \\ $$ Commented…

Find-Q-0-x-3-e-x-T-1-dx-where-Q-is-assumed-finite-for-T-being-a-positive-constant-and-Q-taking-the-form-Q-KT-n-where-K-constant-and-n-Z-

Question Number 4298 by Yozzii last updated on 08/Jan/16 $${Find}\:{Q}=\int_{\mathrm{0}} ^{\infty} \frac{{x}^{\mathrm{3}} }{{e}^{{x}/{T}} −\mathrm{1}}{dx}\:,{where}\:{Q}\:{is} \\ $$$${assumed}\:{finite}\:{for}\:{T}\:{being}\:{a}\: \\ $$$${positive}\:{constant},\:{and}\:{Q}\:{taking}\:{the} \\ $$$${form}\:{Q}={KT}^{{n}} \:,{where}\:{K}={constant} \\ $$$${and}\:{n}\in\mathbb{Z}. \\ $$$$…