1) Find the equation of the tangent plane to the graph of the function f(x, y) = (x3 + siny) / (y^2+1) at the point (2, 0, 8).
2) Let g(x, y, z) = x2 - y3 + z4. Let L be the level surface of g containing the point P(3, 2, 1). Find the equation of the tangent plane to the surface L at the point P.
The equations of a plane and a tangent plane are found using gradients. The solution is detailed and well presented.