An object is thrown upward from the ground with an initial velocity of 48 feet per second. The height h(t) in feet of the object after t seconds is given by the polynomial function h(t)=-16t2+48t . (a) Write an equivalent factored expression for the function h(t) by factoring -16t2+48t.

(b) Find h(4) by using h(t)=-16t2+48t and then by using the factored form of h(t).

(c) Why are the values found in part (b) the same?