f[x_]:=x^3+(Sqrt[5*x])
g[x_]:=x^2(Sqrt[((20*x)/(2+3*x-1))])

Plot[{f[x],g[x]},{x,0,1},Filling->{1->{{2},RGBColor[0,0,1]}},ClippingStyle->Red,Frame->True,Mesh->Full,MeshStyle->Directive[PointSize[Medium],Red],FrameStyle->Pink]

h[x_,y_]:=(x^2+y^2)/5*x+2*y

h1[x_,y_]:=-(x^2+y^2)/5*x+2*y

Plot3D[{h[x,y],h1[x,y]},{x,-10,10},{y,-10,10},ColorFunction->"BlueGreenYellow", BoundaryStyle->Directive[Red,Thick],Filling->{1->{2,RGBColor[0,0,1]}}]