math
posted by Clary .
The height of a ball above the ground t seconds after it is thrown is h(t)= 20 + 32t  16t^2. How long will it take for the ball to hit the ground? (Round your answer to the nearest hundredth of a second.)

just set h=0 and solve for t. It's just a normal quadratic equation. If you factor out a 4, you can work with smaller numbers.