1) Find first partial derivatives of the function f 2) Is the function f differentiable at the point (0, 0) ? Why ?
3) Find the stops of the function f
4) Does the function f reach its maximum at points (0, 0) and (±1, 0) ? Why ?
5) Find the maximum and minimum values of the function f on the domain D

Amass weighing 16 pounds stretches a spring 8/3 feet. the mass is initially released from rest from a point 2 feet below the equilibrium position, and the subsequent motion takes place in a medium that offers a damping force that is numerically equal to 1/2 the instantaneous velocity. find the equation of motion if the mass is driven by an external force equal to f(t)=cos(2t).