Question 4. Suppose f : R2 - R satisfies sin(x f (x, y)) - xy =x2 for all points (x, y), and f(2, -2) = 0. 4.1. Find the partial derivatives of f at (2, -2). 4.2. Let g(t) = f(10 - +3, t2 - 6). Find g'(2). Hint: when t = 2, (10 - t3, t2 - 6) = (2, -2)