Find minimum or maximum of multi-variable function

[teerasak]

@jlind, Thank you. It is time to come back to review multi-variable calculus which has gone from my head. Thank you for the info and link.

@parissee, you are right. So the minimum for this case is the distance between two point, which is 41. However, I’m not sure, in HP prime, is there the command to find Min/max of multi-variable function? One tools I use is 3D graph. It helps but quite difficult to read the value, and no tools to find extremum in the graph.

@roadrunner, I faced the same issue too. For this problem, I zoom out few time to see the 3D graph. After I quit from the plot, and come back, the scale go back to default.