Category: Trigonometry

Question Number 143348 by gsk2684 last updated on 13/Jun/21 $$\mathrm{if}\frac{\cos {}^4\mathrm{x}}{\cos {}^2\mathrm{y}}+\frac{\sin {}^4\mathrm{x}}{\sin {}^2\mathrm{y}}=1\mathrm{then}$$$$\mathrm{find}\frac{\cos {}^4\mathrm{y}}{\cos {}^2\mathrm{x}}+\frac{\sin {}^4\mathrm{y}}{\sin {}^2\mathrm{x}}=?$$ Answered by som(math1967)…

Question Number 12132 by tawa last updated on 14/Apr/17 $$\mathrm{Given}\mathrm{that}1°=0.017\mathrm{rad}$$$$\mathrm{Use}\mathrm{f}\left(\mathrm{a}\right)=\sin \left(\mathrm{a}\right)\mathrm{to}\mathrm{find}\mathrm{an}\mathrm{approximate}\mathrm{value}\mathrm{for}\sin \left(29\right)°.$$ Answered by mrW1 last updated on 14/Apr/17 $$\frac{\mathrm{\Delta }y}{\mathrm{\Delta }x}=\frac{f(x+\mathrm{\Delta }x)-f\left(x\right)}{\mathrm{\Delta }x}\approx \frac{dy}{dx}$$$$\Rightarrow\:{f}\left({x}+\Delta{x}\right)\approx{f}\left({x}\right)+\frac{{dy}}{{dx}}\Delta{x} \…

Question Number 12085 by chux last updated on 12/Apr/17 Answered by ajfour last updated on 12/Apr/17 $$let6°=\theta$$$$\sin 24°=2\sin 12°\cos 12°$$$$let\sin 12°=xand\cos 12°=y$$$$\sin (3\theta +2\theta )=y\sin 18°+x\cos 18°$$$$\Rightarrow\:{x}\mathrm{cos}\:\mathrm{18}°+{y}\mathrm{sin}\:\mathrm{18}°\:=\mathrm{sin}\:\mathrm{5}\theta=\frac{\mathrm{1}}{\mathrm{2}}…

Question Number 12063 by tawa last updated on 10/Apr/17 Answered by b.e.h.i.8.3.4.1.7@gmail.com last updated on 11/Apr/17 $$100+4(180-a)=360\Rightarrow 4a=820-360$$$$4a=460\Rightarrow a=115.\mathrm{<img\; draggable="false"\; role="img"\; class="emoji"\; alt="◼"\; src="https://s.w.org/images/core/emoji/15.1.0/svg/25fc.svg">}$$ Terms of Service Privacy…

Question Number 12028 by tawa last updated on 09/Apr/17 $$\mathrm{Express}:\sin \left(33\right)\mathrm{in}\mathrm{surd}\mathrm{form}.$$ Answered by sandy_suhendra last updated on 10/Apr/17 $$\mathrm{let}\mathrm{A}=18°$$$$5\mathrm{A}=90°$$$$\mathrm{3A}=\mathrm{90}°−\mathrm{2A} \…