Which function has the greater maximum value

The max value of g(x) is a little more than 5.

What is the max of f(x)?  Find the vertex of f(x) = -2x^2 + 8x - 1.
Here a = -2, b = 8; and c = -1.

Then the vertex x-coordinate is  x = -8/(2[-2]), or   x = 8/4, or x = 2.

The y coord. of the vertex, which is the max of f(x), is f(2) = 7.

f(x) has the larger maximum, because 7 is greater than "a little more than 6."