Category: Trigonometry

Question Number 10916 by okhema last updated on 02/Mar/17 $$findallpossiblevaluesofcos\theta such$$$$that2{cot}^2\theta +cos\theta =0$$ Answered by sandy_suhendra last updated on 02/Mar/17 $$\frac{\mathrm{2cos}^{\mathrm{2}} \theta}{\mathrm{sin}^{\mathrm{2}} \theta}\:+\:\mathrm{cos}\theta\:=\mathrm{0}…

Question Number 76439 by mathocean1 last updated on 27/Dec/19 $$\mathrm{solve}\mathrm{in}[0;2\pi [$$$$1+2\sin 3x⩽0$$ Answered by john santu last updated on 27/Dec/19 $${sin}\mathrm{3}{x}=−\frac{\mathrm{1}}{\mathrm{2}}.\rightarrow{x}=\left\{\mathrm{10}^{{o}} ,\mathrm{50}^{{o}} ,\mathrm{130}^{{o}}…

Question Number 10873 by Saham last updated on 28/Feb/17 $$\mathrm{without}\mathrm{using}\mathrm{calculator}\mathrm{or}\mathrm{table},\mathrm{find}\mathrm{the}\mathrm{exact}\mathrm{value}\mathrm{of}:$$$$\sin \left[{\tan }^{-1}\left(\frac{1}{2}\right)\right]$$ Answered by fariraihmudzengerere75@gmail.c last updated on 28/Feb/17 $${Answer}\:\:\:.\:\mathrm{sin}\:\left[\mathrm{tan}^{−\mathrm{1}} \left({x}\right)\right]={x}/\sqrt{\left(\mathrm{1}+\boldsymbol{\mathrm{x}}\frac{\mathrm{2}}{}\right)} \…

Question Number 10836 by okhema last updated on 27/Feb/17 $$solvecos2\theta -3cos\theta =1$$$$foro⩽\theta ⩽2\pi$$ Answered by ridwan balatif last updated on 27/Feb/17 $$\cos 2\theta -3\cos \theta =1$$$$\left(\mathrm{2cos}^{\mathrm{2}}…

Question Number 10788 by okhema last updated on 25/Feb/17 $$factorisetheexpressionsin4x-sinx$$ Answered by argemiroQR last updated on 26/Feb/17 $$sin(3x+x)-sinx=$$$$sin3xcosx+cos3xsinx-sinx=$$$${cosx}\left(\mathrm{3}{sinx}−\mathrm{4}{sin}^{\mathrm{3}} {x}\right)+\left({cos}^{\mathrm{3}}…