Question

The function g(n) = n2 − 16n + 69 represents a parabola.

Part A: Rewrite the function in vertex form by completing the square. Show your work. (6 points)

Part B: Determine the vertex and indicate whether it is a maximum or a minimum on the graph. How do you know? (2 points)

Part C: Determine the axis of symmetry for g(n). (2 points)

Answer 1

Explanation:

A) y + ? = n^2 - 16n + ? + 69

y + 64 = n^2 -16n + 64 + 69

y + 64 = (n-8)^2 + 69

y = (n-8)^2 + 5

B) vertex is (8,5) because the value of a vertex is always (h,k) from the parent vertex function:

y = a(x-h) + k

it's a minimum only because the (a) value is positive

C) axis of symmetry = 8