i need help with the question in this link
i dont understand part b and c
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trigonometyr functions and equations watch
- Thread Starter
- 12-03-2018 20:17
- 12-03-2018 20:29
Idk which bit of b and c you specified so I'll just explain each bit.
iii) and c
4tan4xsin4x = 15
Let's think of this as tan x, and sin x, and find those roots
express tan x as sin x/cos x, multiply through by sin x to get 4sin^2x/cos x = 15, multiply through by cos x and use the sin^2 + cos^2 = 1 identity specific to this situation, you should obtain a disguised quadratic in cos x, the same quadratic you solved, the only thing left now is to divide your roots by 4, as this is 4x.