jee-advanced 2001 Q18

jee-advanced · India · screening 3x3 Matrices Determinant of Parametric or Structured Matrix
18. The number of distinct roots of $\left| \begin{array} { l } \sin x \cos x \cos x \\ \cos x \sin x \cos x \\ \cos x \cos x \sin x \end{array} \right| = 0$ in the interval $- \frac { \pi } { 4 } \leq x \leq \frac { \pi } { 4 }$ is:
(A) 0
(B) 2
(C) 1
(D) 3
18. The number of distinct roots of\\
$\left| \begin{array} { l } \sin x \cos x \cos x \\ \cos x \sin x \cos x \\ \cos x \cos x \sin x \end{array} \right| = 0$ in the interval $- \frac { \pi } { 4 } \leq x \leq \frac { \pi } { 4 }$ is:\\
(A) 0\\
(B) 2\\
(C) 1\\
(D) 3\\