定积分定义动画演示

402

Clear[f, x, a, b];
2 R4 Z6 v( l' N- [+ Uf[x_]： = x^2; a = 0; b = 1.5; m = 0;
3 d" S: i- S( l* e& C$ y5 {& ]g1 = Plot[f[x], {x, a, b}, PlotStyle -> {RGBColor[1, 0, 0]},
   DisplayFunction -> Identity];
+ ?( c. R9 Z3 `9 X* Y" dFor[j = 3, j <= 50, j += 2, m = j; tt1 = {}; tt2 = {};
. z4 C* C4 U# P& d8 B! ~ For[i = 0, i < m, i++, x1 = a + i*(b - a)/m; x2 = x1 + (b - a)/m;
: C; d% o9 i) s0 J6 W  i1 R2 @( }  tt1 = Append[tt1,
+ h8 z! a. @: a  M1 ?7 |' H    Graphics[{RGBColor[0, 0, 1], Rectangle[{x1, 0}, {x2, f[x2]}]}]];
) N! d; W4 O, M; m  tt2 = Append[tt2,
    Graphics[{RGBColor[0, 0, 1], Rectangle[{x1, f[x1]}, {x2, 0}]}]]];
Show[tt1, tt2, g1, DisplayFunction -> $DisplayFunction,
  PlotLabel -> m'' intervals'']]

/ V. K8 i- {8 i9 C# c" U5 }& p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？

- m/ K) \/ z: Of[x_] := x^2 + 1; a = 0; b = 2; m = 0;
) o2 x0 S& q% V2 r! ^g = Plot[f[x], {x, a, b}, PlotStyle -> Red,
  DisplayFunction -> Identity]
( H. x2 X* o1 L9 A, `- u. ^For[n = 0, n < 100, n = n + 4; t1 = {}; t2 = {};
( U1 d$ ^0 F, U) Q9 U$ v' b) O 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]}]}]];
3 |7 b% r% |, ]& h7 K! g5 \+ c$ l  t2 = Append[t2, Graphics[{Green, Rectangle[{x1, f[x1]}, {x2, 0}]}]]];
, M; f- \4 h0 k2 `) l8 Q Show[t1, t2, g, DisplayFunction -> $DisplayFunction,
9 |, `  Y6 u( I. n+ A  PlotLabel -> n "intervals"]]
% p& c  o: r! k5 F! d, q7 |

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' y; F. h! ~3 Y3 K: ^

变动的永恒

太高端，不懂，帮顶

402

已经解决。谢谢小木虫的大虾。
f[x_] := x^2 + 1; a = 0; b = 2; m = 0;
g = Plot[f[x], {x, a, b}, PlotStyle -> Red];
$ z# m. g! h8 jAnimate[t1 = {}; t2 = {};
For[i = 0, i < n, i++, x1 = a + (b - a) i/n; x2 = x1 + (b - a)/n;
' C' }) U! G5 T0 W/ W  t1 = Append[t1,
% k( s0 e6 M; J$ g* y7 z    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]
3 A0 Z) z3 ~7 V) D6 S7 O" W$ w

宏心

牛。牛牛。
/ U) U' `0 m% d8 @+ V/ o

z43742516

收藏起来慢慢看
1 P* o( [' v: C, W, Q* {6 V

z43742516

收藏起来慢慢看
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meiya

好牛，厉害