定积分定义动画演示

402

Clear[f, x, a, b];
f[x_]： = x^2; a = 0; b = 1.5; m = 0;
8 f! G& f3 d2 ~. S+ Y& [7 ?g1 = Plot[f[x], {x, a, b}, PlotStyle -> {RGBColor[1, 0, 0]},
   DisplayFunction -> Identity];
& o% P7 i+ V  O# S& _3 E; F: D% wFor[j = 3, j <= 50, j += 2, m = j; tt1 = {}; tt2 = {};
For[i = 0, i < m, i++, x1 = a + i*(b - a)/m; x2 = x1 + (b - a)/m;
( A& v. ~0 D. p) R' j% D' l- V" k9 k  tt1 = Append[tt1,
    Graphics[{RGBColor[0, 0, 1], Rectangle[{x1, 0}, {x2, f[x2]}]}]];
  tt2 = Append[tt2,
' s! A/ w/ B; n5 r    Graphics[{RGBColor[0, 0, 1], Rectangle[{x1, f[x1]}, {x2, 0}]}]]];
Show[tt1, tt2, g1, DisplayFunction -> $DisplayFunction,
! X3 T7 q( j! w- ?  PlotLabel -> m'' intervals'']]

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？
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f[x_] := x^2 + 1; a = 0; b = 2; m = 0;
g = Plot[f[x], {x, a, b}, PlotStyle -> Red,
  DisplayFunction -> Identity]
5 L: |$ w7 g% V. j2 YFor[n = 0, n < 100, n = n + 4; t1 = {}; t2 = {};
# |+ t" j1 l, {) Z For[i = 0, i < n, i++, x1 = a + (b - a) i/n; x2 = x1 + (b - a)/n;
& [* f. {% V& R) t+ x( w$ c( l  t1 = Append[t1,
- X6 O' J7 J0 S) k! c    Graphics[{Blue, Rectangle[{x1, f[x1]}, {x2, f[x2]}]}]];
  r! k, @" q3 X( M( X# U' w# O3 }  t2 = Append[t2, Graphics[{Green, Rectangle[{x1, f[x1]}, {x2, 0}]}]]];
4 l& i& N2 Y1 T4 G9 m$ a Show[t1, t2, g, DisplayFunction -> $DisplayFunction,
  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。
1 q- Y' X3 P6 s- Hf[x_] := x^2 + 1; a = 0; b = 2; m = 0;
g = Plot[f[x], {x, a, b}, PlotStyle -> Red];
Animate[t1 = {}; t2 = {};
4 y/ Z) m/ k4 x1 a, P- N9 }) B For[i = 0, i < n, i++, x1 = a + (b - a) i/n; x2 = x1 + (b - a)/n;
- }7 G, t3 y3 ~4 w  t1 = Append[t1,
    Graphics[{Blue, Rectangle[{x1, f[x1]}, {x2, f[x2]}]}]];
8 ?$ s& d$ ?8 i9 L  t2 = Append[t2, Graphics[{Green, Rectangle[{x1, f[x1]}, {x2, 0}]}]]];
Show[t1, t2, g, PlotLabel -> n "intervals"], {n, 4, 100, 4},
. v$ D( t. \4 d3 D  L% O, d; Y* c% [1 V AnimationRunning -> False]
" F2 |8 N! ^: I/ B  \! V- I

宏心

牛。牛牛。
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z43742516

收藏起来慢慢看
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z43742516

收藏起来慢慢看

meiya

好牛，厉害