Question Number 151638 by mathdanisur last updated on 22/Aug/21 $$\underset{\:\mathrm{0}} {\overset{\:\mathrm{2}\boldsymbol{\pi}} {\int}}\left(\mathrm{1}\:-\:\mathrm{cos}\boldsymbol{\mathrm{x}}\right)^{\mathrm{10}} \:\mathrm{cos}\left(\mathrm{10x}\right)\:\mathrm{dx}\:=\:? \\ $$ Answered by Olaf_Thorendsen last updated on 22/Aug/21 $$\mathrm{I}\:=\:\int_{\mathrm{0}} ^{\mathrm{2}\pi} \left(\mathrm{1}−\mathrm{cos}{x}\right)^{\mathrm{10}}…
Question Number 20551 by Tinkutara last updated on 28/Aug/17 $${Find}\:{the}\:{minimum}\:{value}\:{of} \\ $$$$\mid{a}\:+\:{b}\omega\:+\:{c}\omega^{\mathrm{2}} \mid,\:{where}\:{a},\:{b}\:{and}\:{c}\:{are}\:{all} \\ $$$${not}\:{equal}\:{integers}\:{and}\:\omega\left(\neq\mathrm{1}\right)\:{is}\:{a}\:{cube} \\ $$$${root}\:{of}\:{unity}. \\ $$ Commented by ajfour last updated on…
Question Number 20552 by ajfour last updated on 28/Aug/17 $${The}\:{roots}\:{of}\:{the}\:{equation}\: \\ $$$$\:\left(\mathrm{3}−{x}\right)^{\mathrm{4}} +\left(\mathrm{2}−{x}\right)^{\mathrm{4}} =\left(\mathrm{5}−\mathrm{2}{x}\right)^{\mathrm{4}} \:{are} \\ $$$$\left({a}\right)\:{all}\:{real}\:\:\:\:\left({b}\right)\:{all}\:{imaginary} \\ $$$$\left({c}\right)\:{two}\:{real}\:{and}\:{two}\:{imaginary} \\ $$$$\left({d}\right){none}\:{of}\:{the}\:{above}\:. \\ $$ Answered by…
Show-that-if-z-1-z-2-z-3-z-4-0-and-z-1-z-2-0-then-the-complex-numbers-z-1-z-2-z-3-z-4-are-concyclic-
Question Number 20549 by Tinkutara last updated on 28/Aug/17 $${Show}\:{that}\:{if}\:{z}_{\mathrm{1}} {z}_{\mathrm{2}} \:+\:{z}_{\mathrm{3}} {z}_{\mathrm{4}} \:=\:\mathrm{0}\:{and}\:{z}_{\mathrm{1}} \:+ \\ $$$${z}_{\mathrm{2}} \:=\:\mathrm{0},\:{then}\:{the}\:{complex}\:{numbers}\:{z}_{\mathrm{1}} , \\ $$$${z}_{\mathrm{2}} ,\:{z}_{\mathrm{3}} ,\:{z}_{\mathrm{4}} \:{are}\:{concyclic}. \\…
Question Number 20550 by Tinkutara last updated on 28/Aug/17 $${Find}\:{the}\:{equation}\:{of}\:{circle}\:{in}\:{complex} \\ $$$${form}\:{which}\:{touches}\:{iz}\:+\:\bar {{z}}\:+\:\mathrm{1}\:+\:{i}\:=\:\mathrm{0} \\ $$$${and}\:{for}\:{which}\:{the}\:{lines}\:\left(\mathrm{1}\:−\:{i}\right){z}\:= \\ $$$$\left(\mathrm{1}\:+\:{i}\right)\bar {{z}}\:{and}\:\left(\mathrm{1}\:+\:{i}\right){z}\:+\:\left({i}\:−\:\mathrm{1}\right)\bar {{z}}\:−\:\mathrm{4}{i}\:=\:\mathrm{0} \\ $$$${are}\:{normals}. \\ $$ Answered by…
Question Number 151616 by mathdanisur last updated on 22/Aug/21 $$\mathrm{let}\:\:\mathrm{f}\left(\mathrm{x}\right)=\frac{\boldsymbol{\lambda}+\mathrm{x}}{\mathrm{1}+\mathrm{x}^{\mathrm{2}} }\:\:\mathrm{and}\:\:\boldsymbol{\lambda}\geqslant\frac{-\mathrm{3}}{\mathrm{4}} \\ $$$$\mathrm{solve}\:\mathrm{in}\:\mathbb{R}\:\:\:\mathrm{f}\left(\mathrm{f}\left(\mathrm{f}\left(\mathrm{x}\right)\right)\right)\:\leqslant\:\mathrm{0} \\ $$ Commented by mr W last updated on 22/Aug/21 $${then}\:{solution}\:{is}\:{x}\geqslant\lambda \\…
Question Number 86085 by Serlea last updated on 27/Mar/20 $$\mathrm{If}\:\mathrm{X}^{\mathrm{2}} +\mathrm{Y}^{\mathrm{2}} =\mathrm{10} \\ $$$$\:\:\:\:\:\:\:\:\:\:\mathrm{XY}=\mathrm{5} \\ $$$$\mathrm{Find}\:\left(\mathrm{X}^{\mathrm{2}} −\mathrm{Y}^{\mathrm{2}} \right) \\ $$ Commented by jagoll last updated…
Question Number 151614 by mathdanisur last updated on 22/Aug/21 $$\boldsymbol{\Omega}\:=\underset{\:\mathrm{0}} {\overset{\:\mathrm{2}\boldsymbol{\pi}} {\int}}\frac{\mathrm{x}\:+\:\mathrm{tan}\left(\mathrm{sin}\boldsymbol{\mathrm{x}}\right)}{\boldsymbol{\lambda}\:+\:\mathrm{cos}\left(\boldsymbol{\mathrm{x}}\right)}\:\mathrm{dx}\:\:;\:\:\boldsymbol{\lambda}>\mathrm{1} \\ $$ Answered by ArielVyny last updated on 22/Aug/21 $$\Omega=\int_{\mathrm{0}} ^{\mathrm{2}\pi} \frac{{x}+{tan}\left({sinx}\right)}{\lambda+{cos}\left({x}\right)}{dx} \\…
Question Number 151609 by mathdanisur last updated on 22/Aug/21 Answered by ghimisi last updated on 22/Aug/21 $$\Leftrightarrow{log}_{{xy}} \left(\mathrm{1}+\sqrt{{xy}}\right)^{\mathrm{2}} \geqslant{log}_{\frac{{x}+{y}}{\mathrm{2}}} \left(\frac{{x}+{y}}{\mathrm{2}}+\mathrm{1}\right)\Leftrightarrow \\ $$$$\Leftrightarrow\frac{{ln}\left(\mathrm{1}+\sqrt{{xy}}\right)}{{ln}\sqrt{{xy}}}\geqslant\frac{{ln}\left(\mathrm{1}+\frac{{x}+{y}}{\mathrm{2}}\right)}{{ln}\frac{{x}+{y}}{\mathrm{2}}}\:\:\left(\bullet\right) \\ $$$${f}\left({t}\right)=\frac{{ln}\left(\mathrm{1}+{t}\right)}{{lnt}},{f}:\left(\mathrm{1};\infty\right)\rightarrow{R} \\…
Question Number 151599 by mathdanisur last updated on 22/Aug/21 $$\Omega\:=\underset{\:\mathrm{0}} {\overset{\:\infty} {\int}}\mathrm{cos}\left(\mathrm{x}^{\boldsymbol{\mathrm{n}}} \right)\:\mathrm{dx}\:=\:? \\ $$ Answered by Lordose last updated on 22/Aug/21 $$ \\ $$$$\Omega\:\overset{\mathrm{x}=\mathrm{x}^{\frac{\mathrm{1}}{\mathrm{n}}}…