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Category: Algebra

Find-the-cube-root-of-55-63-2-

Question Number 17018 by tawa tawa last updated on 29/Jun/17 $$\mathrm{Find}\:\mathrm{the}\:\mathrm{cube}\:\mathrm{root}\:\mathrm{of}:\:\:\:\mathrm{55}\:+\:\mathrm{63}\:\sqrt{\mathrm{2}} \\ $$ Commented by prakash jain last updated on 29/Jun/17 $$\left({a}+{b}\sqrt{\mathrm{2}}\right)^{\mathrm{3}} =\mathrm{55}+\mathrm{63}\sqrt{\mathrm{2}} \\ $$$${a}^{\mathrm{3}}…

cos-n-x-sinx-dx-

Question Number 148077 by mathdanisur last updated on 25/Jul/21 $$\int\:\frac{{cos}^{\boldsymbol{{n}}} {x}}{{sinx}}\:{dx}\:=\:? \\ $$ Answered by Olaf_Thorendsen last updated on 26/Jul/21 $$\mathrm{I}_{{n}} \left({x}\right)\:=\:\int\frac{\mathrm{cos}^{{n}} {x}}{\mathrm{sin}{x}}\:{dx} \\ $$$$…

If-for-positive-integers-a-and-b-a-b-a-b-b-a-find-a-2-b-2-

Question Number 16990 by 1234Hello last updated on 29/Jun/17 $$\mathrm{If}\:\mathrm{for}\:\mathrm{positive}\:\mathrm{integers}\:{a}\:\mathrm{and}\:{b}, \\ $$$${a}\:+\:{b}\:=\:\frac{{a}}{{b}}\:+\:\frac{{b}}{{a}},\:\mathrm{find}\:{a}^{\mathrm{2}} \:+\:{b}^{\mathrm{2}} . \\ $$ Commented by RasheedSoomro last updated on 29/Jun/17 $${a}\:+\:{b}\:=\:\frac{{a}}{{b}}\:+\:\frac{{b}}{{a}} \\…

Question-82519

Question Number 82519 by peter frank last updated on 22/Feb/20 Commented by mathmax by abdo last updated on 23/Feb/20 $${A}_{\theta} =\sum_{{n}=\mathrm{0}} ^{\infty} \:\frac{\left(−\mathrm{1}\right)^{{n}} }{\mathrm{2}^{{n}} }{cos}\left({n}\theta\right)\:\:=\sum_{{n}=\mathrm{0}}…

2-2-8-6-4-2-8-2-2-8-

Question Number 148043 by mathdanisur last updated on 25/Jul/21 $$\frac{\left(\mathrm{2}\:−\:\sqrt{\mathrm{2}}\right)^{\mathrm{8}} \:\centerdot\:\left(\mathrm{6}\:+\:\mathrm{4}\sqrt{\mathrm{2}}\right)^{\mathrm{8}} }{\left(\mathrm{2}\:+\:\sqrt{\mathrm{2}}\right)^{\mathrm{8}} }\:=\:? \\ $$ Answered by iloveisrael last updated on 25/Jul/21 $$\left[\:\frac{\left(\mathrm{2}−\sqrt{\mathrm{2}}\right)\left(\mathrm{6}+\mathrm{4}\sqrt{\mathrm{2}}\right)}{\mathrm{2}+\sqrt{\mathrm{2}}}\:\right]^{\mathrm{8}} \: \\…

17-4-15-144-1-4-

Question Number 148042 by mathdanisur last updated on 25/Jul/21 $$\sqrt{\mathrm{17}\:−\:\mathrm{4}\sqrt{\mathrm{15}}}\:−\:\sqrt[{\mathrm{4}}]{\mathrm{144}}\:=\:? \\ $$ Answered by Olaf_Thorendsen last updated on 25/Jul/21 $$\mathrm{X}\:=\:\sqrt{\mathrm{17}−\mathrm{4}\sqrt{\mathrm{15}}}−\sqrt[{\mathrm{4}}]{\mathrm{144}} \\ $$$$\mathrm{X}\:=\:\sqrt{\left(\mathrm{2}\sqrt{\mathrm{3}}−\sqrt{\mathrm{5}}\right)^{\mathrm{2}} }−\sqrt[{\mathrm{4}}]{\mathrm{12}^{\mathrm{2}} } \\…

if-f-g-x-2x-5-and-f-x-x-2-find-g-x-

Question Number 148035 by mathdanisur last updated on 25/Jul/21 $${if}\:\:\:{f}\left({g}\left({x}\right)\right)\:=\:\mathrm{2}{x}\:-\:\mathrm{5}\:\:{and}\:\:{f}\left({x}\right)\:=\:{x}\:+\:\mathrm{2} \\ $$$${find}\:\:\:{g}\left({x}\right)\:=\:? \\ $$ Commented by prakash jain last updated on 25/Jul/21 $${f}\left({x}\right)={x}+\mathrm{2} \\ $$$${f}\left({g}\left({x}\right)\right)={g}\left({x}\right)+\mathrm{2}…