Let z = g (x , y ) = x3 + xy2 - 2x + 1, where x = r cos (0) and y = r sin(0). Use the chain rule to find dz at ( r , 0) = (2 , 4 3 .). Enter an integer or a fully reduced fraction such as -2 , 7, -3/4 , 41/7 etc. No spaces please