Question

定义：a是不为1的有理数,我们把1/1-a称为a的差倒数.如：2的差倒数是1/1-2=-1,-1的差倒数是

Answer 1

a2 = 1/(1-1/2) = 1/(1/2) = 2

a3 = 1/(1-2) = 1/(-1) = -1

a4 = 1/(1-(-1)) = 1/2 = a1

a2010 = a(3+2007) = a(3+3*669) = a3 = -1