Question

What is the maximum value that the graph of `y= -x^2 +5x -1`?

Answer 1

`y = 21/4`

Explanation:

`y = - x^2 + 5x - 1`

`y' = - 2x + 5`

`y' = 0 implies x = 5/2 implies y = 21/4`

we know from the shape that it's a max but checking anyways....

`y'' = -2 < 0`, so yes