Category: Trigonometry

Question Number 154240 by amin96 last updated on 15/Sep/21 $$\{\begin{array}{l}tg(a+b)=7\\ tg(a-b)=5\end{array}tg\left(a\right)=?easyquestion$$ Answered by mr W last updated on 15/Sep/21 $$a+b={\tan }^{-1}7$$$${a}−{b}=\mathrm{tan}^{−\mathrm{1}} \mathrm{5}…

Question Number 88613 by ajfour last updated on 11/Apr/20 Commented by ajfour last updated on 11/Apr/20 $$Finda/b.$$ Commented by ajfour last updated on…

Question Number 88567 by jagoll last updated on 11/Apr/20 $$(1+\cos \frac{\pi }{11})(1+\cos \frac{3\pi }{11})(1+\cos \frac{5\pi }{11})(1+\cos \frac{7\pi }{11})(1+\cos \frac{9\pi }{11})$$ Commented by jagoll last updated on 11/Apr/20 $$\mathrm{T}=\left(2\cos {}^2\left(\frac{\pi }{22}\right)\right)\left({2\cos }^2\left(\frac{3\pi }{22}\right)\right)\left(2\cos {}^2\left(\frac{5\pi }{22}\right)\right)$$$$\left(\mathrm{2cos}\:^{\mathrm{2}}…

Question Number 23009 by ajfour last updated on 25/Oct/17 Commented by ajfour last updated on 25/Oct/17 $$ForQ.22929$$ Commented by selestian last updated on…

Question Number 88507 by jagoll last updated on 11/Apr/20 $$\cos {}^2{12}^{\mathrm{o}}+\cos {}^2{24}^{\mathrm{o}}+\cos {}^2{48}^{\mathrm{o}}+\cos {}^2{84}^{\mathrm{o}}$$ Commented by john santu last updated…