Question 1032259
The function has f'(x) = 2x-10 = 0 at the maximum / minimum point.
That means, 2x = 10 so x = 5, hence, y = 5^2 - 10*5 + 21 = 25-50+21 = -4
The max / min is at (5, -4)
f''(x) = 2 > 0 Therefore is a minimum