Question

已知a=2-根号3,化简求值a-1分之1-2a+a平方-a平方-a分之根号a平方-2a+1-a分之1

Answer 1

0<a=2-根号3<1
a-1分之1-2a+a平方-a平方-a分之根号a平方-2a+1-a分之1
=(1-2a+a^2)/(a-1)+[根号(a^2-2a+1)]/(a^2-a)-1/a
=-1+1/a-1/a
=-1

Answer 2

a>0
a-1<0

（a^2-2a+1）/(a-1)-√(a^2-2a+1)/(a^2-a)-1/a
=(a-1)^2/(a-1)-√(a+1)^2/a(a-1)-1/a
=a-1-(1-a)/a/(a-1)-1/a
=a-1+1/a-1/a
=a-1
=1-√3