PLEASE HELP! Python question, I keep getting it wrong :$($

Consider the function $f(x,y)=x^{2}si{n}^{3}y+2\frac{y^3}{\sqrt[\phantom{2}]{x}}.$

Define Python function gradf$(x,y)$ which for each point $(x,y)$ with $x>0$ gives the

gradient gradf$(x,y)=(f_x(x,y),f_y(x,y))$ as Python's tuple object.