定积分定义动画演示

402

Clear[f, x, a, b];
" i' J/ T- A& d( l2 }f[x_]： = x^2; a = 0; b = 1.5; m = 0;
3 _2 U9 R* k1 r2 Y! R* J) eg1 = Plot[f[x], {x, a, b}, PlotStyle -> {RGBColor[1, 0, 0]},
! s$ a1 D/ Q( e9 E   DisplayFunction -> Identity];
# u( [% m# D# J8 ^+ cFor[j = 3, j <= 50, j += 2, m = j; tt1 = {}; tt2 = {};
, b( J$ a+ |' | For[i = 0, i < m, i++, x1 = a + i*(b - a)/m; x2 = x1 + (b - a)/m;
0 j& ]0 d5 I, z3 Z1 [& _. ~  tt1 = Append[tt1,
    Graphics[{RGBColor[0, 0, 1], Rectangle[{x1, 0}, {x2, f[x2]}]}]];
  tt2 = Append[tt2,
    Graphics[{RGBColor[0, 0, 1], Rectangle[{x1, f[x1]}, {x2, 0}]}]]];
Show[tt1, tt2, g1, DisplayFunction -> $DisplayFunction,
  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？

# J- A  x9 U" g5 s5 g! mf[x_] := x^2 + 1; a = 0; b = 2; m = 0;
g = Plot[f[x], {x, a, b}, PlotStyle -> Red,
  DisplayFunction -> Identity]
For[n = 0, n < 100, n = n + 4; t1 = {}; t2 = {};
0 [7 `: |$ L/ E, l$ O For[i = 0, i < n, i++, x1 = a + (b - a) i/n; x2 = x1 + (b - a)/n;
' x$ A7 z. @# L* X  t1 = Append[t1,
- v' x- G: H1 _5 {. e- @  Z    Graphics[{Blue, Rectangle[{x1, f[x1]}, {x2, f[x2]}]}]];
9 _- w( a2 a$ l' }, W  t2 = Append[t2, Graphics[{Green, Rectangle[{x1, f[x1]}, {x2, 0}]}]]];
/ |4 X  j+ |: a  ? Show[t1, t2, g, DisplayFunction -> $DisplayFunction,
2 e: a' [3 F0 ?4 P0 j- S  PlotLabel -> n "intervals"]]

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变动的永恒

太高端，不懂，帮顶
, N+ Q. E. t* t

402

已经解决。谢谢小木虫的大虾。
f[x_] := x^2 + 1; a = 0; b = 2; m = 0;
' X4 F$ Z" S  y) V2 @0 yg = Plot[f[x], {x, a, b}, PlotStyle -> Red];
7 v7 s% U( v  o6 dAnimate[t1 = {}; t2 = {};
: R, \) t- e* d9 D# N" W. i+ d For[i = 0, i < n, i++, x1 = a + (b - a) i/n; x2 = x1 + (b - a)/n;
  t1 = Append[t1,
" ~) c# t1 C0 r% D- R: I    Graphics[{Blue, Rectangle[{x1, f[x1]}, {x2, f[x2]}]}]];
  p& H! D; C' Q* ^& u  t2 = Append[t2, Graphics[{Green, Rectangle[{x1, f[x1]}, {x2, 0}]}]]];
Show[t1, t2, g, PlotLabel -> n "intervals"], {n, 4, 100, 4},
: o4 u$ Z, v4 Y; L3 T/ y  Q  m6 ? AnimationRunning -> False]
. G" `. G& m3 k/ b; L/ c0 ^  }

宏心

牛。牛牛。
, H7 S4 l3 W, w

z43742516

收藏起来慢慢看
: T1 W8 ]  z( U! ^2 e

z43742516

收藏起来慢慢看

meiya

好牛，厉害
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