How can I derive these formulas? Basic 2D motion.?

In the link is a general solution for the two dimensional motion of an object thrown in a gravitational field. This is usually termed a projectile motion problem. The thrown object is called the projectile. Its path is called the trajectory. It answers all the usual questions that arise in a first year physics cl regarding this motion.Without air resistance, the projectile will follow a parabolic trajectory. The projectile is thrown on level ground on planet Earth. It will leave the point of release, arc through the air along a path shaped like a parabola, and then hit ground a certain distance from where it was thrown. See link for all formulae.