A square with side length is inscribed inside a circle.Denote by thearea of the region inside the circle, and outside the square(the shaded region in the diagram).

How would you express as a functionof?

a) S = a²

b) S = (-2)a²/2

c) S = a²-a²

c) S = (-1)a²/2

d) S = (-1)a²/4