A particle is projected from a point O on horizontal ground. The velocity of projection has magnitude 20ms^-I and direction upwards at an angle θ to the horizontal. The particle passes through the point, which is 7m above the ground and 16m horizontally from O, and hits the ground at the point A.

i. Using the equation of the particle's trajectory and the identity sec² θ = 1 + tan² θ, show that the possible values of tan θ are 3/4 and 17/4.

ii. Find the distance Oil for each of the two possible values of tan θ.

iii. Sketch in the same diagram the two possible trajectories.