Here:

(1), the parabolic opening is downward, and the symmetry axis can be obtained from the parabolic analytical formula as x=2, and √ 2- 1 < 2 < √ 2+ 1, so the function has a maximum value when x=2.

(2) The opening of the parabola is upward, and the axis of symmetry of the parabola is x=2. The function has a maximum value when √ 2- 1 < x < √ 2+ 1.

I don't know if what I said is what you asked. Can I help you?