'función a resolver
Public Function g(x) As Double
g = Exp(-x) - x
End Function
'derivada de g(x)
Public Function dg(x) As Double
h = 0.000001
dg = (g(x + h) - g(x)) / h
End Function
'bisección
Public Function biseccion(a, b, n)
If g(a) * g(b) > 0 Then
MsgBox ("la función tiene el mismo signo en ambos extremos")
End If
If g(a) * g(b) = 0 Then
If g(a) = 0 Then
s = a
Else
s = b
End If
Else
For i = 1 To n
s = (a + b) / 2
If g(a) * g(s) < 0 Then
b = s
Else
a = s
End If
Next i
End If
biseccion = s
End Function
'newton raphson
Public Function newtonraphson(x0, n) As Double
xi=x0
For i = 1 To n
xi_1 = xi - g(xi) / dg(xi)
xi = xi_1
Next i
newtonraphson = xi_1
End Function
'punto fijo
Public Function ptofijo(x0, n)
xi=x0
For i = 1 To n
x_i = g(xi) + xi
xi = xi_1
Next i
ptofijo = x_i
End Function
