What is the vertex of the quadratic function shown and indicate whether it is a minimum or maximum value? f(x)=x^2-8x-11

Question

Answer options:

a. (4, -27), maximum b. (-4,27), maximum c. (-4,27) minimum d. (4, -27) maximum

Answer 1

the coordinate of the vertex is at -b/2a

which is -(-8)/2= 4

to find the y value substitute 4 for x

(4)^2 -8(4) -11= 16 -32 -11= -27

So vertex is at (4,-27)

This is an upward facing parabola since the coefficient of the x^2 term is positive. Therefore the vertex is a minimum