A quadratic equation may be expressed in vertex form as: y = a(x - h)² + k, the vertex being (-h , k) For option A, the vertices are visibly different. (-4 , 0) and (4 , 0) For B, the graphs' vertices are the same, (0 , 0). For C, the vertices (can be obtained by differentiating and putting equal to 0) are (0 , -4) and (0 , 4) For D, the vertices are (4 , 0) and (0 , 4) Thus, the answer is B.
