Evaluate the limit or prove that it does not exist.. f(x,y) -> (0,0) 3xy/((x^2)+(4y^2)) The attempt at a solution: Set x to 0 and you get 0 set y to 0 and you get 0 set y=x and you get 3x^2/5x^2 = 3/5 This means that limit does not exist. Is this correct? If this is correct, how do you know that you have to set y=x? Is there a generic approach to these kinds of problems? Thank you for taking the time to read this and for your help.