Hello!!! I am doing a question about curve sketching and determining extrema and just need some clarification. Here is the question: Determine the extreme values of the function f(x) = x^2 - 8x + 9, where -1 is greater than or equal to x is less than or equal to 5. This is what I have done so far: I decided to check for stationary points, as extreme values may occur at f'(0)=0. f'(x) = 2x-8 2x-8 = 0 x = 4 f(4) = 4^2 - 8(4) +9 = -7 (4,-7) may be a max, min or neither. f(3.9) = (3.9)^2 - 8(3.9)+9 = -6.99 f(4.1) = (4.1)^2 - 8(4.1)+9 = -6.99 Does this mean that this point cannot be used in determining the absolute minimum? I am totally lost at this point. I was going to use the endpoints given to figure out the maximum, but I'm not sure if that is an acceptable method. Thanks for any help you can give me.