Public Function vertex(a, b, c)
    back1 = b^2 - (c * (a * 2)^2)
    back2 = (a * 2)^2
    tempGCF = gcf(back1, back2)
    back1 = back1/ (-tempGCF)
    back2 = back2 / tempGCF
    If back2 < 0 Then
        back1 = -back1
        back2 = -back2
    End If
    tempGCF = gcf(b, a * 2)
    b1 = b / tempGCF
    b2 = a * 2 / tempGCF
    If b2 < 0 Then
        b1 = -b1
        b2 = -b2
    End If
    answerstring = a & "(x + " & b1 & "/" & b2 & ")^2 + " & back1 & "/" & back2
    answerstring = Replace(answerstring, "+ -", "- ")
    answerstring = Replace(answerstring, "/1)", ")")
    If Right(answerstring, 2) = "/1" Then answerstring = Left(answerstring, Len(answerstring) - 2)
    If Left(answerstring, 2) = "1(" Then answerstring = Right(answerstring, Len(answerstring) - 1)
    If Left(answerstring, 3) = "-1(" Then answerstring = "-" & Right(answerstring, Len(answerstring) - 2)
    vertex = answerstring
End Function