Category: Trigonometry

Question Number 185212 by Rupesh123 last updated on 18/Jan/23 Terms of Service Privacy Policy Contact: info@tinkutara.com

Question Number 185134 by emmanuelson123 last updated on 17/Jan/23 Answered by som(math1967) last updated on 17/Jan/23 $$\frac{{sin}^{4}x}{5}+\frac{{(1-{sin}^{2}x)}^2}{7}=\frac{1}{12}$$$$\Rightarrow\mathrm{7}{sin}^{\mathrm{4}} {x}+\mathrm{5}−\mathrm{10}{sin}^{\mathrm{2}} {x}+\mathrm{5}{sin}^{\mathrm{4}} {x}=\frac{\mathrm{35}}{\mathrm{12}}…

Question Number 185101 by emmanuelson123 last updated on 17/Jan/23 Answered by Frix last updated on 17/Jan/23 $$\mathrm{In}\mathrm{triangle}a,b,c:$$$$D=\sqrt{(a+b+c)(b+c-a)(a+c-b)(a+b-c)}$$$$$$$${a}^{\mathrm{2}} +{b}^{\mathrm{2}} −\mathrm{2}{ab}\mathrm{cos}\:\gamma\:={c}^{\mathrm{2}}…

Question Number 119506 by bemath last updated on 25/Oct/20 $$\cos \frac{\pi }{5}\cos x+\sin \frac{\pi }{5}\sin x⩽\frac{\sqrt{2}}{2}$$ Answered by 1549442205PVT last updated on 25/Oct/20 $$\cos \frac{\pi }{5}\cos x+\sin \frac{\pi }{5}\sin x⩽\frac{\sqrt{2}}{2}$$$$\iff \cos (\mathrm{x}-\frac{\pi }{5})⩽\cos \frac{\pi }{4}$$$$\Leftrightarrow\mathrm{x}−\frac{\pi}{\mathrm{5}}\geqslant\frac{\pi}{\mathrm{4}}+\mathrm{2m}\pi \…

Question Number 119421 by bemath last updated on 24/Oct/20 $$findthevalueof\underset{i=1}{\prod ^{999}}\cos \left(ia\right);wherea=\frac{2\pi }{1999}$$ Commented by MJS_new last updated on 24/Oct/20 $$\mathrm{study}\:{P}_{{n}} =\underset{{j}=\mathrm{1}} {\overset{{n}} {\prod}}\mathrm{cos}\:\frac{\mathrm{2}\pi{j}}{\mathrm{2}{n}+\mathrm{1}}\:\mathrm{to}\:\mathrm{find}\:\mathrm{the}\:\mathrm{answer}…