Many people probably do not occur in that question, if a = 0, it will be a parabola?? what. The answer is, it's not a parabola heat it will not, however, be a curve linear equations.
Many still question arises in mind that if a = 0, then why would it be? The answer is, it is not parabolic, parabolic tight. It is not, then the curve But it is a linear equation.