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Category: Trigonometry

Solve-the-equation-for-reals-cos-2-x-1-5-sin-2-x-1-sin-2-x-1-5-cos-2-x-1-5tan-2-x-

Question Number 154216 by EDWIN88 last updated on 15/Sep/21 $${Solve}\:{the}\:{equation}\:{for}\:{reals}\: \\ $$$$\:\frac{\mathrm{cos}\:^{\mathrm{2}} {x}−\frac{\mathrm{1}}{\mathrm{5}}\mathrm{sin}\:^{\mathrm{2}} {x}+\mathrm{1}}{\mathrm{sin}\:^{\mathrm{2}} {x}−\frac{\mathrm{1}}{\mathrm{5}}\mathrm{cos}\:^{\mathrm{2}} {x}+\mathrm{1}}\:=\:\mathrm{5tan}\:^{\mathrm{2}} {x}\: \\ $$ Answered by MJS_new last updated on…

1-cos-pi-11-1-cos-3pi-11-1-cos-5pi-11-1-cos-7pi-11-1-cos-9pi-11-

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