已知x=根号3+1,求x方-1分之2x—x+1分之1的值.
问题描述：
已知x=根号3+1,求x方-1分之2x—x+1分之1的值.
答
2x/(x^2-1) -1/(x+1)
=2x/(x^2-1) -(x-1)/(x^2-1)
=(2x-x+1)/(x^2-1)
=(x+1)/(x^2-1)
=1/(x-1)
=1/(根号3+1-1)
=1/(根号3)
=(根号3)/3