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;
; X6 }: K2 J7 R1 {! A- kg1 = Plot[f[x], {x, a, b}, PlotStyle -> {RGBColor[1, 0, 0]},
, F5 b3 J7 |2 x1 `( J   DisplayFunction -> Identity];
+ b& _# E# a5 B: OFor[j = 3, j <= 50, j += 2, m = j; tt1 = {}; tt2 = {};
! v  U* `( a) ] For[i = 0, i < m, i++, x1 = a + i*(b - a)/m; x2 = x1 + (b - a)/m;
$ B9 x+ {- D' w3 _0 t8 [  tt1 = Append[tt1,
  I& ?! A% f& \; O5 Q, z    Graphics[{RGBColor[0, 0, 1], Rectangle[{x1, 0}, {x2, f[x2]}]}]];
8 T1 w# R, F. k6 X  tt2 = Append[tt2,
; m" t4 a6 r: e    Graphics[{RGBColor[0, 0, 1], Rectangle[{x1, f[x1]}, {x2, 0}]}]]];
  J1 b: h' L9 g 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？
, ^% Y3 N, w. A0 A: T* H- }" Z7 x7 X
5 v+ d$ T/ k( \f[x_] := x^2 + 1; a = 0; b = 2; m = 0;
g = Plot[f[x], {x, a, b}, PlotStyle -> Red,
  DisplayFunction -> Identity]
( }2 |. M( C7 B- |+ hFor[n = 0, n < 100, n = n + 4; t1 = {}; t2 = {};
3 a1 r7 J/ m" |! `, E3 M" k For[i = 0, i < n, i++, x1 = a + (b - a) i/n; x2 = x1 + (b - a)/n;
  t1 = Append[t1,
: s) _# g$ V7 f# }' B: K# g7 I    Graphics[{Blue, Rectangle[{x1, f[x1]}, {x2, f[x2]}]}]];
  t2 = Append[t2, Graphics[{Green, Rectangle[{x1, f[x1]}, {x2, 0}]}]]];
Show[t1, t2, g, DisplayFunction -> $DisplayFunction,
# n* a4 X$ W! N/ s  PlotLabel -> n "intervals"]]

! K8 ]1 b$ r: f1 n" |/ M, g
5 H# D( w" v% m( b& X" j

变动的永恒

太高端，不懂，帮顶
/ q: [/ I/ k  H9 X

402

已经解决。谢谢小木虫的大虾。
& A4 ~: V  {0 Ef[x_] := x^2 + 1; a = 0; b = 2; m = 0;
! J& e* T6 e4 J: c0 ?+ Mg = Plot[f[x], {x, a, b}, PlotStyle -> Red];
" U3 c" ~3 B) G( u: z; J0 e  iAnimate[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]
$ A/ r* Z9 m: w% o" _) I/ [

宏心

牛。牛牛。
( N6 G4 j) P3 {0 a& M

z43742516

收藏起来慢慢看

z43742516

收藏起来慢慢看
% A+ o6 c6 Z7 Z/ D& l+ i. }

meiya

好牛，厉害