Question

The functions f(x) = −(x − 1)2 + 5 and g(x) = (x + 2)2 − 3 have been rewritten using the completing-the-square method. Apply your knowledge of functions in vertex form to determine if the vertex for each function is a minimum or a maximum and explain your reasoning.

Answer 1

Answer:

The vertex form of a quadratic function:

(h,k) - the coordinates of the vertex

If a>0, then the parabola opens upwards, so the vertex is the minimum of the function.

If a<0, then the parabola opens downwards, so the vertex is the maximum of the function.