当X=根号2-2时,求（X²-1）（2/X-1 +1/X+1）的值当x=√2-2 时,求（x²-1）（x-1分_数学解答

当X=根号2-2时,求（X²-1）（2/X-1 +1/X+1）的值
当x=√2-2 时,求（x²-1）（x-1分之2 + x+1分之1）的值

人气：458 ℃　时间：2020-05-07 19:52:07

解答

答：
(x^2-1)*[2/(x-1)+1/(x+1)]
=(x^2-1)*[2(x+1)/(x^2-1)+(x-1)/(x^2-1)]
=(x^2-1)*(2x+2+x-1)/(x^2-1)
=3x+1
=3(√2-2)+1
=3√2-5