Calculate the area of triangle WXY with altitude YZ, given W(2, −1), X(6, 3), Y(7, 0), and Z(5, 2). 8 square units
9.4 square units
7.7 square units
12 square units

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).