1. (Restatement) A projectile fired from a catapult moves according to the parametric equations


x(t) = (v0 cos a)t +x0,

y(t) = -1/2 g t^2 + (v0 sin a)t + y0



where (x0, y0) is the starting point of the projectile, v0 is the initial velocity, a is the angle of elevation of the launch of the projectile from horizontal, and g is the acceleration due to gravity (either 32 ft/sec^2 or 9.81 m/sec^2). The functions x(t) and y(t) give the coordinates of the projectile at time t in seconds. This model does not take into consideration air resistance.