What is the axis of symmetry of h (x) = 5x2 + 40x + 64?

x = - 16

x = - 4

x = 4

x = 16

To the answer of your question Answer C: x = - 4

The graph of a quadratic function is a parabola. The axis of symmetry of a parabola is a vertical line that divides the parabola into two similar halves. The axis of symmetry always passes through the vertex of the parabola. The x - coordinate of the vertex is the equation of the axis of symmetry of the parabola. For the function h (x) = 5x^2 + 40x + 64 we write it in vertex form as follows: h (x) = 5 (x^2 + 8x) + 64 h (x) = 5 (x^2 + 8x + 16) + 64 - 5 (16) h (x) = 5 (x + 4) ^2 + 64 - 80 h (x) = 5 (x - (-4)) ^2 - 16 Thus the vertex is given by (h, k) = (-4, - 16) Therefore, the axis of symmetry of h (x) = 5x^2 + 40x + 64 is the line x = - 4