Function visualiser​
​Step 1:​
​​
​Replace the right hand side of this expression with any expression in terms of x

In[]:=
f[x_]:=xSin[x](*ThenSHIFT+Return*)

This code defines the visualization. The inputs are the function and minimum and maximum values for x

In[]:=
visualize[f_,a_,b_]:=Manipulate[​​Show[{Plot[f[x],{x,a,b}],​​Graphics[{Red,Thick,Arrow[{{i,0},{i,f[i]},{0,f[i]}}],Blue,​​PointSize[.015],Tooltip[Point[{i,f[i]}],{i,f[i]}]},​​PlotRange{{a,b},{f[a],f[b]}},AxesTrue]}],{i,a,​​b,.1}]

Run the function by replacing a and b with minium and maximum values for x

visualize[f,-10,10](*ThenSHIFT+Return;usethesliderorplussigntomoveacrosstheplot*)
Out[]=
​
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