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Category: Trigonometry

1-calculate-A-cos-pi-7-cos-2pi-7-cos-3pi-7-2-calculate-B-tan-pi-7-tan-2pi-7-tan-3pi-7-

Question Number 39028 by maxmathsup by imad last updated on 01/Jul/18 $$\left.\mathrm{1}\right)\:{calculate}\:\:{A}={cos}\left(\frac{\pi}{\mathrm{7}}\right).{cos}\left(\frac{\mathrm{2}\pi}{\mathrm{7}}\right).{cos}\left(\frac{\mathrm{3}\pi}{\mathrm{7}}\right) \\ $$$$\left.\mathrm{2}\right)\:{calculate}\:{B}\:={tan}\left(\frac{\pi}{\mathrm{7}}\right).{tan}\left(\frac{\mathrm{2}\pi}{\mathrm{7}}\right).{tan}\left(\frac{\mathrm{3}\pi}{\mathrm{7}}\right). \\ $$ Answered by tanmay.chaudhury50@gmail.com last updated on 02/Jul/18 $${A}×\mathrm{2}{sin}\frac{\Pi}{\mathrm{7}}=\mathrm{2}{sin}\frac{\Pi}{\mathrm{7}}{cos}\frac{\Pi}{\mathrm{7}}{cos}\frac{\mathrm{2}\Pi}{\mathrm{7}}{cos}\frac{\mathrm{3}\Pi}{\mathrm{7}} \\…

determinant-0-4-1-1-4-0-0-1-3-5-2-1-2-2-5-1-

Question Number 169702 by Anyangwa last updated on 06/May/22 $$\begin{vmatrix}{\mathrm{0}}&{\mathrm{4}}&{\mathrm{1}}&{\mathrm{1}}\\{\mathrm{4}}&{\mathrm{0}}&{\mathrm{0}}&{\mathrm{1}}\\{\mathrm{3}}&{\mathrm{5}}&{\mathrm{2}}&{\mathrm{1}}\\{\mathrm{2}}&{\mathrm{2}}&{\mathrm{5}}&{\mathrm{1}}\end{vmatrix}=\: \\ $$ Answered by MikeH last updated on 06/May/22 $$\mathrm{Identify}\:\mathrm{the}\:\mathrm{row}\:\mathrm{with}\:\mathrm{maximum}\:\mathrm{number} \\ $$$$\mathrm{of}\:\mathrm{zeros}. \\ $$$$−\mathrm{4}\left(\mathrm{4}\left(\mathrm{2}−\mathrm{5}\right)+\left(\mathrm{15}−\mathrm{4}\right)\right)+\left(\mathrm{4}\left(\mathrm{5}−\mathrm{2}\right)−\mathrm{0}+\left(\mathrm{6}−\mathrm{10}\right)\right. \\…

Question-38618

Question Number 38618 by tawa tawa last updated on 27/Jun/18 Commented by MrW3 last updated on 28/Jun/18 $$\left[\mathrm{1}−\frac{\mathrm{1}}{\mathrm{2}}\left(\mathrm{1}−{x}\right)\right]^{\mathrm{4}} =\mathrm{1}−\mathrm{4}{x}+{px}^{\mathrm{2}} +{qx}^{\mathrm{3}} +… \\ $$$${this}\:{can}\:{not}\:{be}\:{true}. \\ $$$$\Rightarrow{something}\:{is}\:{wrong}\:{with}\:{the}\:{question}.…