# How do you tell whether the function has a max or min and identify the coordinates of it #f(x)=-x^2+6x+4#?

##### 1 Answer

Dec 25, 2016

Max. at vertex (3, 13)

#### Explanation:

Since a = -1 < 0, the parabola graph opens downward. There is a max. at the vertex.

x- coordinate of vertex:

y-coordinate of vertex:

f(3) = - 9 + 18 + 4 = 13

Max. at Vertex (3, 13)

graph{- x^2+ 6x + 4 [-40, 40, -20, 20]}