Hi,
Perhaps you can try to put "Show" inside "Manipulate", see the example below:
f[x_] := a x^2;
data = Table[{-3 + 3 i 0.02, f[-3 + 3 i 0.02] /. a -> 1 }, {i, 0, 100}];
Manipulate[
Show[
Show[ListPlot[data], Plot[f[x] /. a -> A, {x, -3, 3}]]
]
, {A, 1, 2}]
I.M.
