The function has a maximum at (1, 3).
_____
You know it is not a minimum because the coefficient of the squared term is negative.
You know the vertex is (1, 3) because you match the pattern to
.. y = a(x -h)^2 +k
which has its vertex at (h, k).
_____
You know it is not a minimum because the coefficient of the squared term is negative.
You know the vertex is (1, 3) because you match the pattern to
.. y = a(x -h)^2 +k
which has its vertex at (h, k).