Sub ZBRAK(X1, X2, N, XB1(), XB2(), NB)
    NBB = NB
    NB = 0
    X = X1
    DX = (X2 - X1) / N
    FP = FUNC(X)
    For I = 1 To N
        X = X + DX
        FC = FUNC(X)
        If FC * FP < 0# Then
            NB = NB + 1
            XB1(NB) = X - DX
            XB2(NB) = X
        End If
        FP = FC
        If NBB = NB Then Exit Sub
    Next I
End Sub