a²-2a+1分之a²-1除以a的三次方-a²分之a+1,其中a=根号3

问题描述:

a²-2a+1分之a²-1除以a的三次方-a²分之a+1,其中a=根号3

原式=[(a+1)(a-1)a²(a-1)]/[(a-1)(a-1)(a+1)]=a²
a=√3 时,原式=a²=√3²=3

((a²-1)/(a²-2a+1))/((a+1)/(a^3-a²))
=a^2(a+1)(a-1)^2/((a-1)^2(a+1)
=a^2=3

a²-2a+1分之a²-1除以a的三次方-a²分之a+1,
=(a+1)(a-1)/(a-1)²÷(a+1)/(a³-a²)
=a²
当a=根号3时,原式=3

a^2-2a+1=(a-1)^2
a^2-1=(a+1)(a-1)
a^3-a^2=a^2(a-1)
所以,原式=[(a+1)/(a-1)]*[a^2(a-1)/(a+1)]=a^2=3