Question

先化简再求值,(a+1分之2 + a平方-1分之a+2)除以a+1分之a 其中a=(-1)2012次方+tan6

Answer 1

答：

题目最后是tan6?没写全吧?是不是tan60°?

[2/(a+1)+(a+2)/(a²-1)]÷[a/(a+1)]

=[2(a-1)+(a+2)]/[(a+1)(a-1)]×(a+1)/a

=3a/[(a+1)(a-1)]×(a+1)/a

=3/(a-1)

a=(-1)^2012+tan60°=1+√3

所以3/(a-1)

=3/(1+√3-1)

=3/√3

=√3