Thanks, but actually I cannot use 'g' with 9.81 m/s^2 or any other 'constant'.
I know it is not usual but 'y0' 'v0' 'd' and 'h' are my constants. 'θ' and 'g' are my variables.
You may consider I'm simulating the projectile on an unknown planet, or if you prefer a planet where the gravity can...