College Alegebra

Question

) A projectile is thrown upward so that its distance above the ground after t seconds is . After how many seconds does it reach its maximum height? What is its maximum height?

Answer 1

Set the expression = 0 to find the time of impact; you need to divide out the t.

Set the derivative = 0 to find the time of the maximum height. If you don't yet have calculus, the maximum height occurs at the vertex of the parabola, i.e. at -240/-20. Find the height from this value of t.