The square at the right has an area of
4. Quarter-circles, centered at two op-
posite vertices of the square, overlap
in the shaded region as shown. What
is the area of the shaded region?

36x2 + 49y2 = 1,764 the foci are located at: (-√13, 0) and (√13,0) (0, -√13) and (0,√13) (-1, 0) and (1, 0)edit: the answer is (- the square root of 13, 0) and (the square root of 13, 0)