胚胎发育不良性神经上皮瘤

Private Sub Command1_Click() Dim x As Double Dim shangxian As Double Dim xiaxian As Double Dim fenge As Double Dim xs As Double Dim n As Integer shangxian = Val(Text1.Text) xiaxian = Val(Text2.Text) fenge = Val(Text3.Text) re = 0 For i = 1 To 1000000000 xs = xiaxian + i * fenge If xs >= shangxian Then xs = shangxian re = xs ^ 2 * fenge + re Exit For End If re = xs ^ 2 * fenge + re Next i List1.AddItem "上限为" & shangxian & ",下限为" & xiaxian & "分割长度为" & fenge & "时, " List1.AddItem "x^2的积分结果为:" & re List1.AddItem " " End Sub *************************矩形法求积分******************************** Option Explicit '用辛普生公式求定积分:S=h/3*(P+2*S2+4*S4) '求积分∫(1/(1+X*X))dx,a=0,b=0.6,允许误差小于0.01 Private Sub Command1_Click() Dim A!, B!, N%, S!, S0!, P!, S2!, S4!, H!, X!, i% A = 0 B = 0.6 N = 2 S0 = 0 P = 1 / (1 + A * A) + 1 / (1 + B * B) Do H = (B - A) / N * 0.5 S2 = 0 X = A + H S4 = 1 / (1 + X * X) For i = 2 To 2 * N - 1 Step 2 X = X + H S2 = S2 + 1 / (1 + X * X) X = X + H S4 = S4 + 1 / (1 + X * X) Next S = H / 3 * (P + 2 * S2 + 4 * S4) If Abs(S - S0) <= 0.01 Then Exit Do S0 = S N = 2 * N Loop MsgBox "S=" & S End Sub