f[x_] := Sin[x]*x; SS1 = Plot[f[x],{x,-3,3},PlotStyle->{RGBColor[0,0,1],Thickness[0.01]}];
SS2[u_] := Graphics[{Blue, PointSize[0.03], Point[{u, f[u]}]}];
SS3[u_] := Graphics[{Red,Thickness[0.01], Line[{{u - 5, f[u] - 5 f'[u]}, {u + 5, f[u] + 5 f'[u]}}]}]; 
SS4[u_] := Graphics[{If[f''[u]<0,Yellow,Purple],Disk[{u,f[u]},0.2]}]; 
Manipulate[ Show[{SS1, SS2[u], SS3[u],SS4[u]}, PlotRange -> {{-3, 3}, {-1, 3}}], {u, -2.5, 2.5}]