Método Numérico de la Secante Calculado con Macros VBA de Excel

1. Cálculo de la raíz de una ecuación no lineal mediante el Método Numérico de la Secante
Utilizando macros de VBA de Excel
Ing. Néstor Augusto Oyarce Linares
naoyarcel@gmail.com

2. aSecanteGrafica - 1
Option Explicit
Sub XY_11_Dic_2020_5()
Dim X As Double, Y As Double, i As Integer
'Método Numérico de LA SECANTE
'14 de Diciembre de 2020, ejercicio 5
Cells.Clear
Cells(1, 1).Value = " ECUACIÓN : "
Cells(3, 1).Value = " X^3+2*X^2+10*X-20"
Cells(1, 2).Value = " ENSAYOS : "
Cells(3, 2).Value = " X "
Cells(3, 3).Value = " Y "
For i = 1 To 10
X = 1 + i / 10
Y = (X) ^ (3) + 2 * (X) ^ (2) + 10 * X - 20
Cells(i + 3, 2).Value = X
Cells(i + 3, 3).Value = Y
If Y > 0 Then Exit For
Next i
Range("A1", "A3").Font.Bold = True
Cells.EntireColumn.AutoFit
End Sub
Sub Crea_grafico()
Dim grafico As ChartObject
Dim wks As Worksheet
Set wks = ActiveWorkbook.Sheets("Hoja1")
Set grafico = wks.ChartObjects.Add(Left:=400, Width:=450, Top:=50, Height:=200)
grafico.Name = "Grafico_1"
grafico.Chart.ChartType = xlXYScatterSmoothNoMarkers
grafico.Chart.SetSourceData Source:=wks.Range("B4:D15")
End Sub
' Ing. Néstor Augusto Oyarce Linares

3. ECUACIÓN : ENSAYOS :
X^3+2*X^2+10*X-20 X Y
1.1 -5.249
1.2 -3.392
1.3 -1.423
1.4 0.664
-6
-5
-4
-3
-2
-1
0
1
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6
Series1
Series2

4. bSecanteCalculo - 1
Option Explicit
Sub Parte2_SECANTE()
Dim Xa As Double, X As Double, Ya As Double, i As Integer, Xb As Double, Xm As Double, Yb As Double
Dim Err As Double, Ym As Double, j As Integer, Y As Double, gx As Double
Cells.Clear
Cells(1, 1).Value = "Método Numérico de la Secante"
Cells(2, 2).Value = "Valor de X"
Cells(2, 3).Value = "Valor de Y"
Cells(2, 5).Value = " Xf "
Cells(2, 6).Value = " Yf "
Cells(2, 7).Value = "Iteraciones"
Xa = 1.3
Xb = 1.4
For j = 1 To 20
Ya = (Xa) ^ (3) + 2 * (Xa) ^ (2) + 10 * Xa - 20
Yb = (Xb) ^ (3) + 2 * (Xb) ^ (2) + 10 * Xb - 20
Xm = Xb - Yb * (Xa - Xb) / (Ya - Yb)
Ym = (Xm) ^ (3) + 2 * (Xm) ^ (2) + 10 * Xm - 20
Err = Abs(Xm - Xb)
Cells(j + 3, 2).Value = Xm
Cells(j + 3, 3).Value = Ym
If Err <= 0.000001 Then Exit For
Xa = Xb
Xb = Xm
Next j
X = Xm
Y = (X) ^ (3) + 2 * (X) ^ (2) + 10 * X - 20
Cells(4, 5).Value = X
Cells(4, 6).Value = Y
Cells(4, 7).Value = j
Range("E1", "E4").Font.Bold = True
Range("E1", "E4").Font.Color = RGB(8, 44, 196)
Cells.EntireColumn.AutoFit
End Sub
' Ing. Néstor Augusto Oyarce Linares

5. Método Numérico de la Secante
Valor de X Valor de Y Xf Yf Iteraciones
1.368183996 -0.013163968 1.368808108 -3.5083E-14 4
1.368802495 -0.000118417
1.368808109 2.13941E-08
1.368808108 -3.5083E-14