How can I prove that: f (x) =∏·ln(x) + √x on domain (0, 15) is strictly concave using the formal definition of concavity?
Can someone help me get started? Thanks!
OK - the formal definition is:
but I just don't know where to go from here. I can't even find similar problems with a google search! Thanks!
Also, the problem just says concave. I assume concave=concave downward and convex=concave upward, right?