i am trying to solve the following problem: find the limit of (xy)/((x^2)+(y^2))^(1/2) as (x,y) approaches (0,0). i know it's kind of hard to read, but that is xy divided by root(x-squared + y-squared). the area where i am having a problem is in my arithmatic. how do i multiply the numerator by root(x-squared + y-squared). i know that it should be able to multiply out, and then cancel out the denominator...and the limit should be 0. i just don't know how to show it. thanks for any help.