The amount of nitrogen dioxide A in parts per million (ppm) that was present in the air in the city of Homer on a certain day in June is modeled by the function
A(t) = -2t^2 + 32t + 12, where t is the number of hours after 6:00 A.M. Use this function to find the time at which the nitrogen dioxide level was at its maximum.
a parabola reaches its max/min midway between the roots. So, at
t = -32/-4 = 8, or 2:00 pm
A(8) = 140