Questions in differentiation

Select	Question
	The ratio of height of cone of maximum volume inscribed in a sphere to its radius is
	The function $f(x)=x+\sin x$ has
	The function $f(x)=ax+\frac{b}{x};a,\,b,x>0$ takes on the least value at x equal to
	If $xy={{c}^{2}},$ then minimum value of $ax+by$ is
	If ${{a}^{2}}{{x}^{4}}+{{b}^{2}}{{y}^{4}}={{c}^{6}},$ then maximum value of xy is
	The function $f(x)=2{{x}^{3}}-15{{x}^{2}}+36x+4$ is maximum at
	Maximum slope of the curve $y=-{{x}^{3}}+3{{x}^{2}}+9x-27$ is
	The function $f(x)=2{{x}^{3}}-3{{x}^{2}}-12x+4$ has
	If $f(x)=\frac{1}{4{{x}^{2}}+2x+1}$ , then its maximum value is
	If $f(x)=x+\frac{1}{x},$ x > 0, then its greatest value is