Please help solve the following four problems:

1. Find dy for the curve 1 + x = sin(xy?). 2. Find the equation of the tangent line to the curve x3 + y = 6ry at the point (3,3). Compute da2 at (3, 3). 3. If 1 + f(x) + x?[f(x)]3 =0 and f(1) = 2, find f'(1). 4. Find the tangent line approximation of f (x) = v1-r at x = 0, and use it to approximate v0.9. Graph f(x) and the linear approximation on the same set of axes