Questions in differentiation

Select	Question
	If $x-2y=4,$ the minimum value of $xy$ is
	The minimum value of $2x+3y,$ when $xy=6,$ is
	The function $f(x)=\|px-q\|+r\|x\|,$ $x\in (-\infty ,\infty )$ where $p>0,q>0,r>0$ assumes its minimum value only at one point if
	The minimum value of function $f(x)=3{{x}^{4}}-8{{x}^{3}}+12{{x}^{2}}-48x+25$ on [0, 3] is equal to
	The maximum value of ${{x}^{1/x}}$ is
	The minimum value of $4{{e}^{2x}}+9{{e}^{-2x}}$ is
	The point $(0,\,5)$ is closest to the curve ${{x}^{2}}=2y$ at
	The maximum value of xy when $x+2y=8$ is
	The minimum value of $P(1,\,1)$ is
	If $P=(1,\,1)$ , $Q=(3,\,2)$ and R is a point on x-axis then the value of $PR+RQ$ will be minimum at