The maximum height is 36.75feet at 2.5 seconds. Using the quadratic equation, you can calculate the x coordinate of the vertex with -b/2a. In this case, the x coordinate of the vertex is the time the swipe card reaches its max height , and it is 2.5. To calculate the maximum height, substitute 2.5 into each variable of t in the original equation, and the solution is 36.75.
