Question 76771
Think about the height of the diver when he/she hits the water!  The diver's height will be zero feet.  So, you can set height in the equation to zero and solve for t.
{{{0 = -16(t-2)(t+1)}}} Apply the zero products principle.
{{{0 = (t-2)(t+1)}}}
So, when height is zero, t = 2 or t = -1
The only answer that is meaningful here is t = 2 seconds.