(a) For $g(x,y) = \sqrt{x^{2}+y+9}$,
$\nabla g(2,3) =$

(b) Find the best linear approximation of $g(x,y)$ for $(x,y)$ near $(2,3)$.
Linear approximation =

(c) Use the approximation in part (b) to estimate $g(2.02, 3.03)$.
$g(2.02,3.03) \approx$