# Thread: Relative extrema question. Did I do it right?

1. ## Relative extrema question. Did I do it right?

Find the x-values of all points where the functions defined as follows have any relative extrema. Find the value(s) of any relative extrema.
f(x)= x^2 - 10x + 33
I did f'(x)= 2x-10
10=2x
x=5
I did a number line and picked 1 and 6. I did 2(1)-10 = - and 2(6)-10= +
f(5)= (5)^2 - 10(5) +33= 8.
f(5)= relative min. of 8 at 5. (That's what the answer from the book)
Dec: (-infinity, 5)
Inc: (5, infinity)
Did I do it right? Thanks

2. Looks right to me.