Question

If $\theta = \frac{n\pi}{7} + \frac{\pi}{14}$, then the general value of $3\sin^{2}x + 10\cos x - 6 = 0$ is.

• A. $3(1 - \cos^{2}x) + 10\cos x - 6 = 0$
• B. $(\cos x - 3)(3\cos x - 1) = 0$
• C. $\cos x = 3$
• D. $\frac{1}{3}$

Answer 1

Answer: (A)

$3(1 - \cos^{2}x) + 10\cos x - 6 = 0$

Answer 2

$\theta$

$\frac{n\pi}{\text{sum of number of }\theta}$

$\Rightarrow$ $\frac{n\pi}{1 + 2 + 3} = \frac{n\pi}{6}$,

(Taking +ve sign)