Question

Is "y=-0.00635x^2+4.0005x" in the correct form to be a Parabola

Answer 1

Yes.

Any parabola is represented by an appropriate second degree polynomial, which means that to identify a particular parabola you have to choose three coefficients
`a,b,c, \in \mathbb{R}` to identify the polynomial

`ax^2+bx+c`

In your case, the expression
`-0.00635x^2+4.0005x` comes from the choice
`a = -0.00635, b = 4.0005, c=0`, and so by all means its graph is a parabola.