定积分定义动画演示

402

Clear[f, x, a, b];
" o: ?1 \1 D7 ]3 [: Pf[x_]： = x^2; a = 0; b = 1.5; m = 0;
; X  j/ P# b# z7 t" C6 ug1 = Plot[f[x], {x, a, b}, PlotStyle -> {RGBColor[1, 0, 0]},
; o9 @* t. p+ ^" p9 z; T% j   DisplayFunction -> Identity];
For[j = 3, j <= 50, j += 2, m = j; tt1 = {}; tt2 = {};
$ j* k5 c' y! O. O1 j& v! f For[i = 0, i < m, i++, x1 = a + i*(b - a)/m; x2 = x1 + (b - a)/m;
; D. ?: ^! J3 U4 v  tt1 = Append[tt1,
    Graphics[{RGBColor[0, 0, 1], Rectangle[{x1, 0}, {x2, f[x2]}]}]];
  tt2 = Append[tt2,
; e% Y7 j! Q( a, Q; \1 L    Graphics[{RGBColor[0, 0, 1], Rectangle[{x1, f[x1]}, {x2, 0}]}]]];
Show[tt1, tt2, g1, DisplayFunction -> $DisplayFunction,
  PlotLabel -> m'' intervals'']]
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2 ]$ R9 `$ D, V" C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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2 d* \' }2 M6 _7 U( Z0 H6 pf[x_] := x^2 + 1; a = 0; b = 2; m = 0;
g = Plot[f[x], {x, a, b}, PlotStyle -> Red,
+ `4 ?7 V+ b8 B  DisplayFunction -> Identity]
8 {0 i& S2 B% d# a, J& F6 \. hFor[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,
    Graphics[{Blue, Rectangle[{x1, f[x1]}, {x2, f[x2]}]}]];
: ~7 s- X- @' y9 q; f  t2 = Append[t2, Graphics[{Green, Rectangle[{x1, f[x1]}, {x2, 0}]}]]];
# A( ]4 z' ]6 {7 q$ ?. n6 h Show[t1, t2, g, DisplayFunction -> $DisplayFunction,
1 R  a) o: @4 x1 R$ A  f4 F9 g/ c# O% L- h  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。
f[x_] := x^2 + 1; a = 0; b = 2; m = 0;
- f1 r0 A2 E0 ~: ~% A$ Cg = Plot[f[x], {x, a, b}, PlotStyle -> Red];
Animate[t1 = {}; t2 = {};
6 _+ v" n$ d- {3 {2 A. a4 r For[i = 0, i < n, i++, x1 = a + (b - a) i/n; x2 = x1 + (b - a)/n;
& D, w( v9 y+ T, O" k; E/ F  t1 = Append[t1,
$ `7 ?" `, h1 s    Graphics[{Blue, Rectangle[{x1, f[x1]}, {x2, f[x2]}]}]];
- ^8 \' F5 h" V# u: p8 F; m  t2 = Append[t2, Graphics[{Green, Rectangle[{x1, f[x1]}, {x2, 0}]}]]];
, M/ _8 e9 Z& U) q Show[t1, t2, g, PlotLabel -> n "intervals"], {n, 4, 100, 4},
AnimationRunning -> False]

宏心

牛。牛牛。

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