Question Number 104904 by bemath last updated on 24/Jul/20 $$\mathrm{4cos}\:^{\mathrm{2}} {x}\:\mathrm{sin}\:{x}\:−\mathrm{2sin}\:^{\mathrm{2}} {x}\:=\:\mathrm{3sin}\:{x} \\ $$$${where}\:−\frac{\pi}{\mathrm{2}}\leqslant{x}\leqslant\frac{\pi}{\mathrm{2}} \\ $$ Answered by bramlex last updated on 24/Jul/20 $$\mathrm{sin}\:{x}\:\left(\mathrm{4cos}\:^{\mathrm{2}} {x}−\mathrm{2sin}\:{x}−\mathrm{3}\right)\:=\:\mathrm{0}…
Question Number 104894 by bramlex last updated on 24/Jul/20 $${prove}\:{that}\:\mathrm{cos}\:^{\mathrm{6}} {a}\:−\mathrm{sin}\:^{\mathrm{6}} {a}\:=\: \\ $$$$\mathrm{cos}\:\mathrm{2}{a}\:\left(\mathrm{1}−\frac{\mathrm{1}}{\mathrm{4}}\mathrm{sin}\:^{\mathrm{2}} \mathrm{2}{a}\right)\: \\ $$ Answered by john santu last updated on 24/Jul/20…
Question Number 170371 by cortano1 last updated on 22/May/22 $$\:{solve}\:\frac{\mathrm{sin}\:\left({x}+\mathrm{18}°\right)}{\mathrm{sin}\:{x}}\:=\:\frac{\mathrm{sin}\:\mathrm{18}°}{\mathrm{sin}\:\mathrm{12}°} \\ $$ Answered by greougoury555 last updated on 22/May/22 $$\:\mathrm{sin}\:\mathrm{18}°=\mathrm{2sin}\:\mathrm{12}°\mathrm{sin}\:\mathrm{48}° \\ $$$$\:\frac{\mathrm{sin}\:\left({x}+\mathrm{18}°\right)}{\mathrm{sin}\:{x}}\:=\:\frac{\mathrm{2sin}\:\mathrm{12}°\:\mathrm{sin}\:\mathrm{48}°}{\mathrm{sin}\:\mathrm{12}°} \\ $$$$\mathrm{sin}\:\left({x}+\mathrm{18}°\right)=\mathrm{2sin}\:{x}\:\mathrm{sin}\:\mathrm{48}° \\…
Question Number 104796 by mathocean1 last updated on 23/Jul/20 $${show}\:{that}\: \\ $$$$\mathrm{8}{cos}^{\mathrm{4}} {x}−\mathrm{8}{cos}^{\mathrm{2}} {x}+\mathrm{1}={cos}\mathrm{4}{x}. \\ $$ Commented by kaivan.ahmadi last updated on 23/Jul/20 $${cos}\mathrm{4}{x}=\mathrm{2}{cos}^{\mathrm{2}} \mathrm{2}{x}−\mathrm{1}=\mathrm{2}\left(\mathrm{2}{cos}^{\mathrm{2}}…
Question Number 104735 by bemath last updated on 23/Jul/20 Commented by 1549442205PVT last updated on 23/Jul/20 $$\boldsymbol{\mathrm{what}}\:\boldsymbol{\mathrm{is}}\:\boldsymbol{\mathrm{your}}\:\boldsymbol{\mathrm{question}}? \\ $$ Commented by bemath last updated on…
Question Number 170262 by alcohol last updated on 19/May/22 $${I}_{{n}} \:=\:\int_{\mathrm{0}} ^{\:\mathrm{1}} {x}^{{n}} \sqrt{\mathrm{1}−{x}^{\mathrm{2}} }\:{dx} \\ $$$${show}\:{that}\:\left({n}+\mathrm{1}\right){I}_{{n}} \:=\:\left({n}+\mathrm{4}\right){I}_{{n}+\mathrm{2}} \\ $$ Terms of Service Privacy Policy…
Question Number 104727 by bemath last updated on 23/Jul/20 $$\mathcal{G}{iven}\:{x}\:+\:\frac{\mathrm{1}}{{x}}\:=\:\mathrm{2cos}\:\theta \\ $$$${find}\:{x}^{{n}} +\frac{\mathrm{1}}{{x}^{{n}} }\:=\:? \\ $$ Commented by bemath last updated on 23/Jul/20 $${thank}\:{you}\:{all} \\…
Question Number 104576 by bemath last updated on 22/Jul/20 $$\mathrm{2sin}\:\mathrm{2}{x}\:−\mathrm{4sin}\:^{\mathrm{2}} {x}\:=\:\mathrm{7cos}\:\mathrm{2}{x} \\ $$$${with}\:\frac{\pi}{\mathrm{2}}<\:{x}\:<\:\pi\: \\ $$$${find}\:\mathrm{sin}\:\mathrm{2}{x}\: \\ $$ Commented by bemath last updated on 22/Jul/20 $${thank}\:{you}\:{both}…
Question Number 39028 by maxmathsup by imad last updated on 01/Jul/18 $$\left.\mathrm{1}\right)\:{calculate}\:\:{A}={cos}\left(\frac{\pi}{\mathrm{7}}\right).{cos}\left(\frac{\mathrm{2}\pi}{\mathrm{7}}\right).{cos}\left(\frac{\mathrm{3}\pi}{\mathrm{7}}\right) \\ $$$$\left.\mathrm{2}\right)\:{calculate}\:{B}\:={tan}\left(\frac{\pi}{\mathrm{7}}\right).{tan}\left(\frac{\mathrm{2}\pi}{\mathrm{7}}\right).{tan}\left(\frac{\mathrm{3}\pi}{\mathrm{7}}\right). \\ $$ Answered by tanmay.chaudhury50@gmail.com last updated on 02/Jul/18 $${A}×\mathrm{2}{sin}\frac{\Pi}{\mathrm{7}}=\mathrm{2}{sin}\frac{\Pi}{\mathrm{7}}{cos}\frac{\Pi}{\mathrm{7}}{cos}\frac{\mathrm{2}\Pi}{\mathrm{7}}{cos}\frac{\mathrm{3}\Pi}{\mathrm{7}} \\…
Question Number 169771 by greougoury555 last updated on 08/May/22 $$\:\:\:\:\:\:\frac{\mathrm{1}}{\mathrm{1}+\mathrm{cos}\:^{\mathrm{2}} {x}}\:+\:\frac{\mathrm{1}}{\mathrm{sin}\:^{\mathrm{2}} {x}+\mathrm{1}}\:=\:\frac{\mathrm{48}}{\mathrm{35}} \\ $$ Answered by kapoorshah last updated on 08/May/22 $${SyberMath} \\ $$ Answered…