For the function \(f(x) = x^{2/3}(2x + 5)\), if: a) \(x = 0\) is a horizontal tangent b) The curve has no asymptote c) The curve has a cusp at \((0,0)\) d) The curve has no vertical tangent Then:
The value of \(\lim_{(x,y) \to (0,0)} \frac{x^2y}{x^2 + y^2}\) is: