f(x)=xe0.5x Solution differentiating we get f\'(x)=e^.5x+.5x*e^.5x for f\'(X)=0 .5x=-1 or x=-2 f\"(x)=.5e^.5x+.25x*e^.5x+.5e^.5x putting x=-2 f\"(x)>0 so x=-2 is a minima f(-2)=-2/e so f will decrease from -infinity to -2 and increase from -2 to infinity for f\"(X)=0,x=-4,so -4 is the point of inflection so the fuction will be concave from -4 to infinity as f\'\'(x)>0.