Category: Trigonometry

Question Number 147581 by EDWIN88 last updated on 22/Jul/21 $$2\sin 2\mathrm{x}-4\sin {}^2\mathrm{x}=7\cos 2\mathrm{x}$$$$\frac{\pi }{2}<\mathrm{x}<\pi \Rightarrow \sin 2\mathrm{x}=?$$ Answered by iloveisrael last updated on 22/Jul/21 $$\:\mathrm{If}\:\mathrm{2sin}\:\mathrm{2x}−\mathrm{4sin}\:^{\mathrm{2}} \mathrm{x}\:=\:\mathrm{7cos}\:\mathrm{2x}\: \…

Question Number 81963 by jagoll last updated on 17/Feb/20 $$if\tan \left(x\right)+\sec \left(x\right)=\frac{7}{8}$$$$find\cot \left(x\right)+\mathrm{cosec}\left(x\right)=$$ Commented by john santu last updated on 17/Feb/20 $$let\cot \left(x\right)+\mathrm{cosec}\left(x\right)=t$$$$\left({i}\right)\:\left\{\mathrm{tan}\:\left({x}\right)+\mathrm{sec}\:\left({x}\right)\right\}×\left\{\mathrm{cot}\:\left({x}\right)+\mathrm{cosec}\:\left({x}\right)\right\}=\:\frac{\mathrm{7}{t}}{\mathrm{8}}…

Question Number 16392 by ajfour last updated on 21/Jun/17 Answered by Tinkutara last updated on 21/Jun/17 Commented by Tinkutara last updated on 21/Jun/17 $$\angle{AMI}\:=\:\mathrm{90}°,\:\angle{MAI}\:=\:\frac{{A}}{\mathrm{2}},\:{s}\:=\:\frac{{a}\:+\:{b}\:+\:{c}}{\mathrm{2}}, \…

Question Number 16358 by Tinkutara last updated on 21/Jun/17 $$\mathrm{In}\mathrm{any}\mathrm{triangle}ABC,a\cot A+b\cot B$$$$+c\cot C\mathrm{is}\mathrm{equal}\mathrm{to}$$$$\left(1\right)r+R$$$$\left(2\right)r-R$$$$\left(3\right)2(r+R)$$$$\left(4\right)2(r-R)$$ Commented by b.e.h.i.8.3.4.1.7@gmail.com…

Question Number 16354 by Tinkutara last updated on 21/Jun/17 Answered by myintkhaing last updated on 21/Jun/17 $$\frac{{b}^{\mathrm{2}} +{c}^{\mathrm{2}} −{a}^{\mathrm{2}} }{\mathrm{2}{bc}}+\frac{{a}^{\mathrm{2}} +{b}^{\mathrm{2}} −{c}^{\mathrm{2}} }{\mathrm{2}{ab}}=\mathrm{2}−\frac{{c}^{\mathrm{2}} +{a}^{\mathrm{2}} −{b}^{\mathrm{2}}…