result when x is [-0.5,0.5) should equals to 25.0/64.0 - x*1.0/8.0*(3.0/4.0 + x*(5.0/2 + x))
result when x is [-0.5,0.5) should equals to 25.0/64.0 - x1.0/8.0(3.0/4.0 + x*(5.0/2 + x))