The value of $$\left( {1 + \cos {\pi \over 6}} \right)\left( {1 + \cos {\pi \over 3}} \right)\left( {1 + \cos {{2\pi } \over 3}} \right)\left( {1 + \cos {{7\pi } \over 6}} \right)$$ is

$$P = {1 \over 2}{\sin ^2}\theta + {1 \over 3}{\cos ^2}\theta $$, then

A positive acute angle is divided into two parts whose tangents are 1/2 and 1/3. Then the angle is

The smallest value of $$5\cos \theta + 12$$ is