Q. The equation $3\sin^{2}{x + 10\cos{x - 6 = 0}}$ is satisfied, if
A) $x = n\pi \pm \cos^{- 1}\left( \frac{1}{3} \right)$
B) $x = 2n\pi \pm \cos^{- 1}\left( \frac{1}{3} \right)$
C) $x = n\pi \pm \cos^{- 1}\left( \frac{1}{6} \right)$
D) $x = 2n\pi \pm \cos^{- 1}\left( \frac{1}{6} \right)$
Explanation
(b)
We have, $3\sin^{2}{x + 10\cos{x - 6 = 0}}$
$\Rightarrow \ (\cos{x - 3)(3\cos{x - 1) = 0}}$
$\Rightarrow \ \cos{x \neq 3\ or\ \cos{x = \frac{1}{3}}}$
$\Rightarrow \ x = 2n\pi \pm \cos^{- 1}\left( \frac{1}{3} \right)$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.