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