Hi there. I'm plotting a tangent plane to a particular surface. However, the range for both x and y if +- sqrt(2), which is +-1.41. The expected value of z for the tangent plane is sqrt(2) as well. However, when i run the command, MATLAB produces an error for that particulat range (produces sucessful output on ranges such as +-2). Would be grateful if someone provided insight what I could do to solve this issue. The code is shown below. Any advice would be greatly apreciated.