10楼: Originally posted by laosam280 at 2013-07-23 11:24:36
当x1<x2时，
sin(x1)/x1 - sin(x2)/x2
= sin(x1)/x1 - sin(x1+x2-x1)/x2
=sin(x1)/x1 - /x2
>=   sin(x1)/x1 - /x2 (这里用了sin(x)<x，因为这可以在单位圆里直接看出来)
= (x2-x1)/(x1x2)
= (x2-x ...

10楼: Originally posted by laosam280 at 2013-07-23 11:24:36
当x1<x2时，
sin(x1)/x1 - sin(x2)/x2
= sin(x1)/x1 - sin(x1+x2-x1)/x2
=sin(x1)/x1 - /x2
>=   sin(x1)/x1 - /x2 (这里用了sin(x)<x，因为这可以在单位圆里直接看出来)
= (x2-x1)/(x1x2)
= (x2-x ...