Hi

I'm afraid you are wrong

A projectile fired with an angle to the horizontal and with his weight as only force acting on it describes a parabola

You can start from the equation of the acceleration

Choosing an appropriate system of axes (O,x,y) O being the point where the projectile is fired, (Ox) being the horizontal directed in the same direction of the motion

Integrating gives the speed

being the initial speed

Integrating again gives the coordinates from which you can find the range and the maximum height and finally

You will find some help on LATEX here

http://www.mathhelpforum.com/math-help/latex-help/