calculate for each function:

a)the range of growth and decreasing

b)local extreme points

c)points of inflection

d)intervals of concavity

e)outline of the graphic

$\displaystyle 1) y=xe^x$

$\displaystyle 2) y=2\sqrt{x}-x$

$\displaystyle 3)y=\frac{e^x}{x}$