science
posted by nt52 .
prove that the maximum horizontal range is 4 times the maximum height attained by a projectile which is fired long the required oblique direction

The maximum range is achieved when θ=π/4
R = v^2 sin2θ/g
h = v^2 sin^2 θ / 2g
R/h = 4cotθ
at θ=π/4, R/h = 4