Multivariable Calculus (MATH-219)Homework #5Due Th 2/27/20 (Sec. 03/04) / F 2/28/20 (Sec. 01)Show work, don't quote Wolfram, do webwork, etc.1. For the functionf(x; y) = (25x2y2)1=2, please sketch the level curves of thefunction, and then list the domain and the range of the function, write down a curvethat represents the boundary, and state whether the domain is an open or closed region.2. For the functionf(x; y) =2y+xxy3write out an equation for a level curve for whichf(x; y) =C. Your nal equationshould be of the formy=f(x; C). What is the level curve that goes through the point(1;2)?3. Evaluate the limitlim(x;y)!(2;2)xyx4y44. Prove that the following limit does not exist:lim(x;y)!(1;1)xy21y15. Find all the rst and second partial derivatives off(x; y) =x2y+ cos(xy) + tanxy.6.