2. Given that z = x3 + y and x3 + y? = 1, determine an expression for dz dx in terms of x and y. 3. If z = f(x, y) =0, show that- dy az The curves 2p3 + 3x-8=0 dx ax ay and x3 + 2xy3 + 3y - 1 =0 intersect at the point (2, -1). Find the tangent of the angle between the tangents to the curves at this point