If a projectile is fired with angle of elevation 6 and initial speed on. Assuming that the only external force is due to gravity, the position of the projectile can be modeled by a vector function in the plane, A; . 'r' (t) : ((1)3 cos (9)15, ('03 S1119) 9132}, vvhere g a 9.8 111/82 is the acceleration due to gravity. What angle of elevation maximizes the distance betvveen the point from which the projectile is fired and the point vvhere it hits the ground