Final answer:
The equation of the axis of symmetry of the quadratic function is x = 2.
Step-by-step explanation:
The axis of symmetry of a quadratic function is a vertical line that passes through the vertex of the parabola represented by the function. The equation of the axis of symmetry can be found by taking the average, or mean, of the x-values of the zeros of the quadratic function.
In this case, the zeros are -4 and 8. So, the average of -4 and 8 is (8+(-4))/2 = 4/2 = 2. Therefore, the equation of the axis of symmetry of the quadratic function is x = 2.