At a constant temperature, the number of moles (n) of an ideal gas is a function of two variables = (,) where P is the pressure and V is the volume (Remember the ideal gas law = , where R is the universal gas constant). The number of moles function is given as = (,) = −2 +4 −2 +6. Find the maximum and minimum values of the number of moles if pressure is changing between [0,4] atmospheres while volume is changing between [0,5] liters.