Question Number 137382 by bramlexs22 last updated on 02/Apr/21 $${The}\:{solution}\:{set}\:{of}\:{equation} \\ $$$$\mathrm{cos}\:^{\mathrm{2}} {x}+\mathrm{cos}\:^{\mathrm{2}} \mathrm{2}{x}+\mathrm{cos}\:^{\mathrm{2}} \mathrm{3}{x}\:=\:\mathrm{1}\: \\ $$$${on}\:\mathrm{0}\leqslant{x}\leqslant\mathrm{2}\pi \\ $$ Commented by MJS_new last updated on…
Question Number 137366 by liberty last updated on 02/Apr/21 $${Find}\:{the}\:{solution}\:{of}\:{equation} \\ $$$$\mathrm{sin}\:^{\mathrm{2}} {x}+\mathrm{sin}\:^{\mathrm{2}} \mathrm{2}{x}+\mathrm{sin}\:^{\mathrm{2}} \mathrm{3}{x}\:=\:\mathrm{1} \\ $$$${on}\:{interval}\:\left(\mathrm{0},\mathrm{2}\pi\right) \\ $$ Answered by benjo_mathlover last updated on…
Question Number 137338 by liberty last updated on 01/Apr/21 $$\mathrm{Given}\:\frac{\mathrm{cos}\:\mathrm{8}\theta+\mathrm{6cos}\:\mathrm{6}\theta+\mathrm{13cos}\:\mathrm{4}\theta+\mathrm{8cos}\:\mathrm{2}\theta}{\mathrm{cos}\:\mathrm{7}\theta+\mathrm{5cos}\:\mathrm{5}\theta+\mathrm{8cos}\:\mathrm{3}\theta}\:=\:\frac{\mathrm{1}}{\mathrm{2}} \\ $$$$\mathrm{then}\:\mathrm{what}\:\mathrm{the}\:\mathrm{value}\:\mathrm{of}\:\mathrm{tan}\:\mathrm{2}\theta\:? \\ $$ Answered by EDWIN88 last updated on 01/Apr/21 $$\mathrm{consider}\:\mathrm{numerator} \\ $$$$\Leftrightarrow\:\mathrm{cos}\:\mathrm{8}\theta+\mathrm{cos}\:\mathrm{6}\theta+\mathrm{5}\left(\mathrm{cos}\:\mathrm{6}\theta+\mathrm{cos}\:\mathrm{4}\theta\right)+\mathrm{8}\left(\mathrm{cos}\:\mathrm{4}\theta+\mathrm{cos}\:\mathrm{2}\theta\right) \\…
Question Number 6225 by sanusihammed last updated on 19/Jun/16 Commented by Rasheed Soomro last updated on 19/Jun/16 $${y}+{x}\:\:{has}\:{not}\:\:{unique}\:{value}. \\ $$ Commented by FilupSmith last updated…
Question Number 6202 by sanusihammed last updated on 18/Jun/16 Commented by Rasheed Soomro last updated on 18/Jun/16 $${What}\:{is}\:{meant}\:{by}\:\:'\:{persegi}\:'?\:{Square}? \\ $$ Answered by Rasheed Soomro last…
Question Number 6183 by Rasheed Soomro last updated on 17/Jun/16 $${Show}\:{that} \\ $$$$\mathrm{180}°−\mathrm{2cos}^{−\mathrm{1}} \:\frac{\mathrm{2}}{\:\sqrt{\mathrm{13}}}=\mathrm{sin}^{−\mathrm{1}} \left(\frac{\mathrm{12}}{\mathrm{13}}\right) \\ $$ Answered by Yozzii last updated on 18/Jun/16 $$\pi−\mathrm{2}{acos}\left(\mathrm{2}/\sqrt{\mathrm{13}}\right)={asin}\left(\mathrm{12}/\mathrm{13}\right)…
Question Number 6148 by saiful last updated on 16/Jun/16 $${if}\:\alpha,\beta\:{and}\gamma\:{is}\:{corner}\:{in}\:\Delta{abc}.\:{indication}\:{that}\:{cos}\left(\beta+\gamma\right)=−{cos}\alpha \\ $$ Answered by Rasheed Soomro last updated on 16/Jun/16 $${cos}\left(\beta+\gamma\right)=−{cos}\alpha \\ $$$$−−−−−−−−−− \\ $$$$\because\alpha,\beta,\gamma\:{are}\:{angles}\:{of}\:{a}\:{triangle}…
Question Number 6146 by Ninik last updated on 16/Jun/16 $${Determine}\:{the}\:{value}\:{of}\:\mathrm{sin}\:\left(\frac{\Pi}{\mathrm{3}}+{p}\right)\mathrm{cos}\:\left(\frac{\Pi}{\mathrm{6}}+{p}\right)−\mathrm{cos}\:\left(\frac{\Pi}{\mathrm{3}}+{p}\right)\mathrm{sin}\:\left(\frac{\Pi}{\mathrm{6}}+{p}\right) \\ $$ Answered by Rasheed Soomro last updated on 16/Jun/16 $$\mathrm{sin}\:\left(\frac{\pi}{\mathrm{3}}+{p}\right)\mathrm{cos}\:\left(\frac{\pi}{\mathrm{6}}+{p}\right)−\mathrm{cos}\:\left(\frac{\pi}{\mathrm{3}}+{p}\right)\mathrm{sin}\:\left(\frac{\pi}{\mathrm{6}}+{p}\right) \\ $$$$\mathrm{sin}\:\alpha\:\mathrm{cos}\:\beta−\mathrm{cos}\:\alpha\:\mathrm{sin}\:\beta=\mathrm{sin}\:\left(\alpha−\beta\right) \\ $$$$=\mathrm{sin}\:\left(\left(\frac{\pi}{\mathrm{3}}+{p}\right)−\left(\frac{\pi}{\mathrm{6}}+{p}\right)\right)…
Question Number 6145 by Ninik last updated on 16/Jun/16 $${show}\:{that}\:\mathrm{sin}\:\mathrm{64}^{°\:} \:×\mathrm{cos}\:\:\mathrm{26}^{°} \:+\:\mathrm{cos}\:\mathrm{64}^{°\:} ×\:\mathrm{sin}\:\mathrm{26}^{°} \:=\mathrm{1}\: \\ $$$$ \\ $$ Answered by Rasheed Soomro last updated on…
Question Number 6131 by love math last updated on 15/Jun/16 $${sin}\:\mathrm{4}{x}+{sin}\mathrm{12}{x}+{sin}\:\mathrm{8}{x} \\ $$ Answered by Irfan hakim last updated on 18/Jun/16 $$\mathrm{sin}\:\mathrm{24}{x} \\ $$ Commented…