Zooming in on 1 D and 2 D Plots

1D Plots

f[x_] := x^3 Cos[4x^2] + Exp[x];
Manipulate[Plot[f[x], {x,center-width/2,center+width/2}], {center,-10,10},{width,1,.01}]

2D Plots

g[x_,y_] := x^3 y^2 + 4 x y - 15 Cos[4 x^2 y] Sin[5 x y] + 4 Exp[-(x^2+y^2)];
Manipulate[Plot3D[g[x,y], {x,xcenter-width/2,xcenter+width/2},{y,ycenter-width/2,ycenter+width/2}],{xcenter,-4,4},{ycenter,-4,4},{width,1,.001}]