A ball is thrown from an initial height of 6 feet with an initial upward velocity of 40 ft/s. The ball's height h (in feet) after t seconds is given by the following. h=6+407-1612
Find all values of t for which the ball's height is 28 feet.
Round your answer(s) to the nearest hundredth.
(If there is more than one answer, use the "or" button.)