Let the straight line x = b divide the area enclosed by y = ( 1 − x ) 2 , y = 0 , and x = 0 into two parts R 1 ( 0 ≤ x ≤ b ) and R 2 ( b ≤ x ≤ 1 ) such that R 1 − R 2 = 1 4 . Then b equals 3 4 1 2 1 3 1 4 be obtained by heating?