Explain why the function is differentiable at the given point. f(x, y) = 1 + x ln(xy − 5), (2, 3) The partial derivatives are fx(x, y) = and fy(x, y) = , so fx(2, 3) = and fy(2, 3) = . Both fx and fy are continuous functions for xy > and f is differentiable at (2, 3). Find the linearization L(x, y) of f(x, y) at (2, 3). L(x, y) =