Plot[2(1/3)^x,{x,-.5,3}]

Direction->1 means “from the left” (and -1 means from the right). Weird. Better to just use “left” and “right”....

Limit[Exp[3/(2-x)],x->2,Direction->1]

f[x_]:=Exp[x]/x^2
Plot[{f[x]},{x,-2,4},PlotRange->{{-2,4},{-1,8}}]

fp[x_]=Simplify[D[f[x],x]]
Plot[{fp[x]},{x,-2,4}]

Solve[fp[x]==0,x]

fpp[x_]=Simplify[D[f[x],{x,2}]]

Solve[fpp[x]==0,x]

Plot[{f[x],fp[x],fpp[x]},{x,-2,4}]