Find the equation of the line from (x, f(x)) to (x*,f(x*)) and use the definition of concave.

If f'(x)= 0, there are three possibilities: x* is a local maximum, a local minimum, or a point of inflection. Show that it must be a local maximum and then a global maximum.b)Given that f(x) is concave, prove that x* is a global maximum of f(x) is and only if f′(x*)= 0

Suppose it had two global maximum and show that leads to a contradiction. You might want to look at the line between the two maxima.c) Given that f(x) is strictly concave, prove that it cannot possess more than one global maximum.

my understanding of graphs is very poor any help on this would be greatly appreciated.

Dave[/QUOTE]