The solution $$\int\limits_0^{\pi /4} {{{\cos }^4}3\theta {{\sin }^3}\,6\theta d\theta \,\,} $$ is :

The infinite series $$1 + x + {{{x^2}} \over {2!}} + {{{x^3}} \over {3!}} + {{{x^4}} \over {4!}} + ........$$ corresponds to

What should be the value of $$\lambda $$ such that the function defined below is continuous at $$x = {\pi \over 2}$$?
$$f\left( x \right) = \left\{ {\matrix{ {{{\lambda \,\cos x} \over {{\pi \over 2} - x}},} & {if\,\,x \ne {\pi \over 2}} \cr {1\,\,\,\,\,\,\,\,\,\,,} & {if\,\,x = {\pi \over 2}} \cr } } \right.$$

The $$\mathop {Lim}\limits_{x \to 0} {{\sin \left( {{2 \over 3}x} \right)} \over x}\,\,\,$$ is