Как устранить возникшие ошибки в коде - VB

Function Amp(ByVal x As Variant)
A = K * Sqr((A1 * x(i) ^ 2 + A3) ^ 2 + (A0 * x(i) ^ 3 - A3 * x(i)) ^ 2) / ((A1 * x(i) ^ 2 + A3) ^ 2 + (A2 * x(i) - A0 * x(i) ^ 3) ^ 2)
Amp = A
End Function
Function Faz(ByVal x As Variant)
F = -Atn(T1 * x(i)) - Atn(T2 * x(i)) - Atn(T3 * x(i))
Faz = F
End Function
 
Private Sub Command1_Click()
Picture1.Scale (-100, 100)-(100, -100)
DrawWidth = 2
Line (-100, 0)-(100, 0)
Line (0, 100)-(-100, 0)
DrawWith = 1
x = Array(0, 0.01, 0.05, 0.1, 0.5, 1, 2, 5, 10, 20, 50, 100, 1000, 10000, 1000000)
For i = LBound(x) To UBound(x)
Line -(A(x(i)), F(x(i)))
Next i
End Sub