The height of a cannon ball, h metres, t seconds, after it has been shot out of a cannon is given by the formula h(t) = -12 - 20t - 5t^2

a. Determine the maximum height of the cannon ball.

b. How long does it take the cannon ball to reach its maximum height?

c. How long does it take the cannon ball to reach the ground?

d. How high off the ground is the cannon ball before it is shot out of the cannon?