Final answer:
The vertex of the parabola is represented by the coordinates (h, k) in the equation y = a(x - h)2 + k.
Step-by-step explanation:
The vertex of a parabola in the form y = a(x - h)² + k is given by the coordinates (h, k). In this case, the equation of the main cable of the suspension bridge is y = a(x - h)² + k, and the vertex is represented by the coordinates (h, k). Therefore, the vertex of the parabola is the point (h, k).