Is what equal to zero, on the right side of equation?
Also, a parabola can be any narrowness or wide, so no you can't solve this.
Any value for a is valid.
Oh wait, you have set y = 0, haven't you? Oh, so there is a solution perhaps.
But you need to know where you want the parabola to pass through the x-axis.
If you know the roots of the equation or the points on the x-axis, then you can
calculate the "a" number.