Determine the extreme values of the function f(x)=x^2-8x+9, where -1≤x≤5. What is the absolute minimum and the absolute maximum?

Answer 1

The graph is a parabola opening upward.

The minimum point will be at x=4 (you can compute the value) which is found by setting the derivative equal to 0. The maximum will be found at one (or the other) end point of the interval.

If you have not yet had calculus, you should know that the minimum point of a parabola ax²+bx+c occurs where x=-b/(2a).