Maxim/minimum extrema derivatives
one model of worldwide oil production is the function given by the following formula where p(t) is the # of barrels in billions produced in a year, t years after 1933. according to this model, in what yaer did worldwide oil production achieve an absolute maximum? what was that maximum?

p(t)=0.218t^4-0.167t^3 0.00156t^2 0.002t 0.22 0 (theyre greater than or equal too)