解:原式=1/2 * 2/3 * 3/4 * 4/5 * 5/6 * 6/7 * 7/8 *8/9 *9/10
=1/10
(中间的项基本都能消掉)
(1/2-1)(1/3-1)(1/4-1)(1/5-1)(1/6-1)(1/7-1)(1/8-1)(1/9-1)(1/10-1)
=(-1/2)(-2/3)(-3/4)......(-9/10)
=-1/10
(1/2-1)(1/3-1)(1/4-1)(1/5-1)(1/6-1)(1/7-1)(1/8-1)(1/9-1)(1/10-1)
=(-1/2)(-2/3)(-3/4)(-4/5)(-5/6)(-6/7)(-7/8)(-8/9)(-9/10)
=-1/10
原式=(-1/2)(-2/3)(-3/4)(-4/5)(-5/6)(-6/7)(-7/8)(-8/9)(-9/10)
=-1/10