関数定義

\(\(\(Remove[
      f]\)\(;\)\(　\)\( (*\ まずリセット*) \)\)\)

f[x_] := x^2 + 3  x;

Plot[f[x], {x, -2, 2}]

Remove[f]

f[x_] := 1;

f[x_] := 
      0  /;  And[ x > 0, 
          x < 1];

?f

Plot[f[x], {x, -10, 10}]

Needs["Graphics`Animation`"]

Animate[
      Plot[t Sin[x], {x, -10, 10}, 
        PlotRange -> {{-10, 10}, {-2, 2}}], {t, 1, 
        2}]