Sоlve the prоblem. Assume the x-аxis is hоrizontаl, the positive y-аxis is vertical (opposite g), the ground is horizontal, and only the gravitational force acts on the objects. A projectile is launched from the origin at an angle of α radians to the horizontal and an initial speed of 75 ft/sec. Find the position function r(t) for this projectile.