"Determine if the force F(r) is conservative (justify your answer) and, if it is, find a potential function in the case

[tex] F(r) = \frac {1} {||r||} (-xi + yj) [/tex]

where r = xi + yj"

I know that F = -grad V where V is the potential function. In order to find the potential function V from the above, do you integrate grad V for each unit vector i and j?

Another thing is, I'm not very sure how to manipulate the r. Would you use the quotient rule in order to find [tex] \frac {dV} {dydx} [/tex] as an example?

If somebody managed to answer the question and display their answer showing how they did it, that would be fantastic!