Question

Derived the path of projections is a parabola

Answer 1

Equation (5) represents the path of the projectile. If we put tan θ = A and g/2u2cos2θ = B then equation (5) can be written as y = Ax - Bx2 where A and B are constants. This is the equation of a parabola. Hence, the path of the projectile is a parabola.