' benoetigt: 1 PictureBox
Option Explicit
Private Sub Form_Activate()
 
   ' Variablen deklarieren
   Dim X#, Y#, Rand#, i%
 
   ' Form einstellen
   Me.WindowState = vbMaximized
   Me.Caption = "Quadratische Parabel"
 
   ' PictureBox einstellen
   Rand = 10
   Picture1.Move Me.ScaleWidth * 0.05, Me.ScaleHeight * 0.05, Me.ScaleWidth * _
     0.9, Me.ScaleHeight * 0.9
   Picture1.Scale (-Rand, Rand)-(Rand, -Rand)
   Picture1.AutoRedraw = True
   Picture1.BackColor = vbWhite
   Picture1.Cls
 
   ' Koordinatensystem zeichnen
   Picture1.Line (0, -Rand)-(0, Rand), vbBlue     ' x-Achse
   Picture1.Line (-Rand, 0)-(Rand, 0), vbBlue     ' y-Achse
 
   ' Startwert
   Picture1.CurrentX = -Rand
   Picture1.CurrentY = f(-Rand)
 
   ' Funktion zeichnen
   For X = -Rand To Rand Step 0.01
      Y = f(X)
      Picture1.Line -(X, Y), vbRed
   Next X
 
End Sub
 
Private Function f(a) As Double
   f = 3 * a * a + 2 * a - 5        ' <-- hier steht die Funktion f(x) = ...
End Function

Gru