Suppose that 0 < c < π / 2 . for what value of c is the area of the region enclosed by the curves y = cos x , y = cos ( x − c ) , and x = 0 equal to the area of the region enclosed by the curves y = cos ( x − c ) , x = π , and y = 0 ? (note: these areas are in the interval 0 ≤ x ≤ π .)