JEE Advance - Mathematics (1984 - No. 14)
Find the values of $$x \in \left( { - \pi , + \pi } \right)$$ which satisfy the equation $${g^{(1 + \left| {\cos x} \right| + \left| {{{\cos }^2}x} \right| + \left| {{{\cos }^3}x} \right| + ...)}} = {4^3}$$
$$\pm \frac{\pi}{6}$$
$$\pm \frac{\pi}{3}$$
$$\pm \frac{\pi}{2}$$
$$\pm \frac{2\pi}{3}$$
$$\pm \pi$$