定积分定义动画演示

402

Clear[f, x, a, b];
6 {* }" [& s( y9 Nf[x_]： = x^2; a = 0; b = 1.5; m = 0;
8 A( e8 C/ v3 o  rg1 = Plot[f[x], {x, a, b}, PlotStyle -> {RGBColor[1, 0, 0]},
8 p% P% u) ]2 Z1 \6 f" ?! J   DisplayFunction -> Identity];
, V& ]4 r2 G) o1 W2 Z0 }; dFor[j = 3, j <= 50, j += 2, m = j; tt1 = {}; tt2 = {};
5 U. X- p- i, e; \2 t( {8 N For[i = 0, i < m, i++, x1 = a + i*(b - a)/m; x2 = x1 + (b - a)/m;
  tt1 = Append[tt1,
    Graphics[{RGBColor[0, 0, 1], Rectangle[{x1, 0}, {x2, f[x2]}]}]];
  tt2 = Append[tt2,
/ ~" F' J* Z: S    Graphics[{RGBColor[0, 0, 1], Rectangle[{x1, f[x1]}, {x2, 0}]}]]];
9 G0 v9 F" s- N1 z Show[tt1, tt2, g1, DisplayFunction -> $DisplayFunction,
  PlotLabel -> m'' intervals'']]
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定积分的动画演示，运行没有结果，请各位大虾看看错在哪里？

f[x_] := x^2 + 1; a = 0; b = 2; m = 0;
5 \6 |7 |; z5 v  Mg = Plot[f[x], {x, a, b}, PlotStyle -> Red,
+ Z; w' m) _: U$ l$ X1 K3 n! Y  DisplayFunction -> Identity]
! T4 G7 e! j7 q) J5 rFor[n = 0, n < 100, n = n + 4; t1 = {}; t2 = {};
For[i = 0, i < n, i++, x1 = a + (b - a) i/n; x2 = x1 + (b - a)/n;
  t1 = Append[t1,
/ P; e: S2 ?1 W5 U    Graphics[{Blue, Rectangle[{x1, f[x1]}, {x2, f[x2]}]}]];
  t2 = Append[t2, Graphics[{Green, Rectangle[{x1, f[x1]}, {x2, 0}]}]]];
* j* Z8 c1 W' i) z, n Show[t1, t2, g, DisplayFunction -> $DisplayFunction,
/ K2 c' C% A: Q/ G: M$ y( x4 k9 d2 R  PlotLabel -> n "intervals"]]



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变动的永恒

太高端，不懂，帮顶
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402

已经解决。谢谢小木虫的大虾。
0 e) ^2 {6 u0 `2 H: ef[x_] := x^2 + 1; a = 0; b = 2; m = 0;
g = Plot[f[x], {x, a, b}, PlotStyle -> Red];
Animate[t1 = {}; t2 = {};
For[i = 0, i < n, i++, x1 = a + (b - a) i/n; x2 = x1 + (b - a)/n;
  t1 = Append[t1,
    Graphics[{Blue, Rectangle[{x1, f[x1]}, {x2, f[x2]}]}]];
  t2 = Append[t2, Graphics[{Green, Rectangle[{x1, f[x1]}, {x2, 0}]}]]];
Show[t1, t2, g, PlotLabel -> n "intervals"], {n, 4, 100, 4},
AnimationRunning -> False]
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宏心

牛。牛牛。
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z43742516

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z43742516

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meiya

好牛，厉害