Aball is thrown from an initial height of 7 feet with an initial upward velocity of 23/fts. the ball's height h (in feet) after t seconds is given by the following.
h=7+23t-16t^2
find all values of t for which the ball's height is 15 feet.
round your answer(s) to the nearest hundredth. (if there is more than one answer, use the "or" button.)