17. If the solution sets of the trigonometric equations $\sin x = 0$ and $\sin 2x = 0$ are $E$ and $F$ respectively, then ( ) (A) $E \subset F$ (B) $E \supset F$ (C) $E = F$ (D) $E \cap F = \varnothing$
Let $\alpha$ and $\beta$ be two real roots of the equation $(k + 1) \tan ^ { 2 } x - \sqrt { 2 } \cdot \lambda \tan x = (1 - k)$, where $k (\neq -1)$ and $\lambda$ are real numbers. If $\tan ^ { 2 } (\alpha + \beta) = 50$, then a value of $\lambda$ is (1) $10 \sqrt { 2 }$ (2) 10 (3) 5 (4) $5 \sqrt { 2 }$
The number of elements in the set $S = \left\{x \in \mathbb{R} : 2\cos\left(\frac{x^2 + x}{6}\right) = 4^x + 4^{-x}\right\}$ is (1) 1 (2) 3 (3) 0 (4) infinite
If the solution of the equation $\log_{\cos x} \cot x + 4\log_{\sin x} \tan x = 1, \quad x \in \left(0, \frac{\pi}{2}\right)$ is $\sin^{-1}\frac{\alpha + \sqrt{\beta}}{2}$, where $\alpha, \beta$ are integers, then $\alpha + \beta$ is equal to: (1) 3 (2) 5 (3) 6 (4) 4
The sum of the solutions $x \in R$ of the equation $\frac { 3 \cos 2 x + \cos ^ { 3 } 2 x } { \cos ^ { 6 } x - \sin ^ { 6 } x } = x ^ { 3 } - x ^ { 2 } + 6$ is (1) 0 (2) 1 (3) - 1 (4) 3
Q83. The number of solutions of $\sin ^ { 2 } x + \left( 2 + 2 x - x ^ { 2 } \right) \sin x - 3 ( x - 1 ) ^ { 2 } = 0$, where $- \pi \leq x \leq \pi$, is $\_\_\_\_$