# Math Help - tough double variable derivative

1. ## tough double variable derivative

$f(x,y)=k(x^2+y^2)^{\frac{arctan\frac{x}{y}}{2}}$

how to make a derivative of f(x,y) by x?

i dont know by what method to work here
?

2. I take it you are finding the partial derivative $\displaystyle \frac{\partial f}{\partial x}$.

Take the derivative as you would normally, treating $\displaystyle y$ as a constant.