Any help with this problem I have would be so much appreciated, i've been going round in circles and have no idea what I'm really doing.
I have the problem:
- Find all local maximum and minimum points of the function $f = xy$.
I've done the first derivative to get $$f' = 1(\frac{dy}{dx})$$
But I have no clue on how to find the local max and min from this. Any help would be grateful.
Thank you.