The maximum value of $$\sin \left( {x + {\pi \over 6}} \right) + \cos \left( {x + {\pi \over 6}} \right)$$ in the interval $$\left( {0,{\pi \over 2}} \right)$$ is attained at

If $$K = \sin \left( {{\pi \over {18}}} \right)\sin \left( {{{5\pi } \over {18}}} \right)\sin \left( {{{7\pi } \over {18}}} \right)$$, then what is the value of K?

The expression $${{\sin \alpha + \sin \beta } \over {\cos \alpha + \cos \beta }}$$ is equal to

If $$\sin \theta = 3\sin (\theta + 2\alpha )$$, then the value of tan ($$\theta$$ + $$\alpha$$) + 2 tan$$\alpha$$ is equal to