1. The problem statement, all variables and given/known data given: w is any bounded 2pi periodic function of one variable. and u(x,y) is a function in cartesian coordinates. show that u(x,y)=r*w(theta) is continous at the origin. 2. Relevant equations u(x,y)=r*w(theta) is equal to v(r,theta) where v is a function in polar coordinates 3. The attempt at a solution I know that the definition of continuity is: f(x) is said to be continuous at x=x0 if the limit of f(x) as x tends to x0 is equal to f(x0). but i dont know how to apply it in this case just that our x0 is the origin but how do i apply this in terms of polar coordinates?