Finding Partial Derivatives with Constrained Variables

Suppose that as in polar coordinates. Find

1.2 Finding limits Graphically To find the limit graphically of a function you have to follow the function from both the positive side and from the negative side of the coordinate system towards the number x approaches. For example, For this function as x approaches -2, if you follow the function from both sides the limit equals 4. 1.3 Finding limits...