'Benotigt wird: eine Picturebox
Option Explicit
Private Sub Form_Activate()
 
' Variablen dimensionieren
Dim XPos#, YPos#, i#, PSW#, PSH#
 
Me.WindowState = vbMaximized
Me.Caption = "Diagramm"
DoEvents
Me.ScaleMode = vbPixels
 
With Picture1
   .ScaleMode = vbPixels
   .AutoRedraw = True
   .Move 10, 10, Me.ScaleWidth * 0.9, Me.ScaleHeight * 0.9
 
   ' erstmal die Tafel wischen
   .Cls
   .BackColor = vbWhite
 
   ' x-Achse zeichnen
   PSW = .ScaleWidth
   PSH = .ScaleHeight
   Picture1.Line (0, PSH / 2)-Step(PSW, 0), vbBlack
 
   ' Startposition
   .CurrentX = 0
   .CurrentY = PSH \ 2
 
   ' Funktion zeichnen
   For XPos = 0 To PSW - 1
      YPos = -f_x(XPos) + PSH / 2
      Picture1.Line -(XPos, YPos), vbRed
   Next XPos
End With
End Sub

Private Function f_x(x As Double) As Double
   ' Definition der Funktion in der Form
   ' f(x) = a * x * x + b * x + c
   f_x = 0.002 * x * x + 1 * x - 200
End Function

Gru