Question

Jen is investigating a quadratic function g(x). She writes four different forms of the function, as shown below. Select the form that reveals the maximum value of g(x) without having to be rewritten.

Answer 1

A

Explanation:

Since the coefficient of the x² term is negative (we know this because if you look at C, the coefficient of x² is -2, which is negative) we know that the vertex will be the maximum. To find the vertex without having to be rewritten, a quadratic function should be written in vertex form which is y = a(x - c)² + d where (c, d) is the vertex. The answer choice that is written in vertex form is A.