Using two kinematics equations, which are the parametric equations, a uniform linear motion in horizontal direction and a non-uniform linear motion in vertical directions, a parabolic trajectory can be obtained.

horizontal direction Link to heading

In $x$ direction ..

$$\tag{1} $$

..

vertical direction Link to heading

In $y$ direction ..

$$\tag{2} $$

..

combining equations Link to heading

Using previous equations ..

$$\tag{3} $$

..