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…
Question Number 137197 by Fikret last updated on 30/Mar/21 $$\alpha\:,\:\beta\:\epsilon\:\left(\mathrm{0}\:,\:\frac{\pi}{\mathrm{2}}\right) \\ $$$${tan}^{\mathrm{2}} \alpha\:=\:\mathrm{1}+\mathrm{2}{tan}^{\mathrm{2}} \beta\:\:\Rightarrow\sqrt{\mathrm{2}}{cos}\alpha−{cos}\beta=? \\ $$ Answered by MJS_new last updated on 31/Mar/21 $$\mathrm{cos}\:{x}\:=\frac{\mathrm{1}}{\:\sqrt{\mathrm{1}+\mathrm{tan}^{\mathrm{2}} \:{x}}}…
Question Number 137103 by Boucatchou last updated on 29/Mar/21 $$\:\:\:\:\:\:\:\:\:{Solve}\:\:\mathrm{3}{cos}\mathrm{5}{x}−\mathrm{4}{sin}\mathrm{4}{x}−\mathrm{3}=\mathrm{0}\:\:{in}\:\mathbb{R} \\ $$ Answered by MJS_new last updated on 30/Mar/21 $$\mathrm{obviously}\:{x}=\mathrm{2}{n}\pi\:\mathrm{is}\:\mathrm{a}\:\mathrm{solution} \\ $$$$\mathrm{the}\:\mathrm{others}\:\mathrm{can}\:\mathrm{only}\:\mathrm{be}\:\mathrm{approximated} \\ $$$${x}\approx.\mathrm{966119}+\mathrm{2}{n}\pi \\…
Question Number 71563 by gunawan last updated on 17/Oct/19 $$\mathrm{find}\:\mathrm{maximum}\:\mathrm{and}\:\mathrm{minimum} \\ $$$$\mathrm{cos}\:{x}+\sqrt{\mathrm{3}}\:\mathrm{sin}\:{x} \\ $$$${for} \\ $$$$\frac{\pi}{\mathrm{6}}\leqslant{x}\leqslant\pi \\ $$ Answered by MJS last updated on 17/Oct/19…
Question Number 137038 by bobhans last updated on 29/Mar/21 $$ \\ $$Given triangle ABC, what is the maximum value of y=2cosA + cosB + cosC?…