Josephood7

Find the linear approximation to [math] at the point [math]:

[math]

Find the linearization [math] of the function [math] at [math].

[math] 

Note: Your answer should be an expression in x and y; e.g. "3x - 5y + 9"

List the points in the [math]-plane, if any, at which the function [math] is not differentiable.

points = 
(If there is more than one point, give them as a comma-separated list, e.g., (1,2),(3,4); if the function is differentiable everywhere, enter the word none.)

Note: You can earn partial credit on this problem.