discontinuous.c running 
a few points of y = f(x) 
x=      0.000000100000, = 3E7AD7F29ABCAF48, y=     -1.000000000000 
x=      0.000001000000, = 3EB0C6F7A0B5ED8D, y=      1.000000000000 
x=      0.100000000000, = 3FB999999999999A, y=     -0.990000000000 
x=      0.300000000000, = 3FD3333333333333, y=      1.000000000000 
x=      0.500000000000, = 3FE0000000000000, y=     -0.750000000000 
x=      0.700000000000, = 3FE6666666666666, y=     -0.510000000000 
x=      0.900000000000, = 3FECCCCCCCCCCCCD, y=      1.000000000000 
x=      0.999999000000, = 3FEFFFFDE7210BE9, y=      1.000000000000 
a few points of y = fd(x) 
x=      0.000000100000, = 3E7AD7F29ABCAF48, y=      0.008777048733 
x=      0.000001000000, = 3EB0C6F7A0B5ED8D, y=      0.017497309126 
x=      0.010000000000, = 3F847AE147AE147B, y=      0.206138839015 
x=      0.323333333333, = 3FD4B17E4B17E4B1, y=      0.543855751286 
x=      0.343333333333, = 3FD5F92C5F92C5F9, y=      0.612572069664 
x=      0.353333333333, = 3FD69D0369D0369D, y=      0.599377854212 
x=      0.363333333333, = 3FD740DA740DA740, y=      0.566762795681 
x=      0.500000000000, = 3FE0000000000000, y=      0.500000000062 
x=      0.500000010000, = 3FE00000055E63B9, y=      0.500003758077 
x=      0.665666666667, = 3FE54D242E6BDC80, y=      0.314742617282 
x=      0.667666666667, = 3FE55D867C3ECE2A, y=      0.347112635025 
x=      0.999999990000, = 3FEFFFFFFAA19C47, y=      0.994740699349 
x=      1.000000000000, = 3FF0000000000000, y=      0.999999060783 
write fdiscontinuous.out, 101 points 
write fddiscontinuous.out, 101 points 
discontinuous.c finished