What is the rate of change of the function f(x,y)= ln( square root( x^2 + y^2)) at (0, square root(e)) in direction towards the origin?
The unit vector would be (0,1), but I have not been able to find the
I thought that I would just plug in and (0,0) into the equation, but that doesn't work because you can't when I plug in (0,0) I get ln(0) which isn't possible.
Do you know what I am doing wrong?