# Question -12

Geometry Level 3

How many distinct real roots $$x$$ satisfy the determinant

$\left | \begin{array}{ccc} \sin x & \cos x & \cos x\\ \cos x& \sin x & \cos x\\ \cos x & \cos x& \sin x \\ \end{array} \right |=0$ lie in the interval $$[-\frac{\pi}{4},\frac{\pi}{4}]$$ ?

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