{(x的三次方-x)分之(x的平方-2x+1)}*(1-x分之1),其中x=根号2-1,.先化简再求值,

问题描述:

{(x的三次方-x)分之(x的平方-2x+1)}*(1-x分之1),其中x=根号2-1,.先化简再求值,

{(x的三次方-x)分之(x的平方-2x+1)}*(1-x分之1)
=(x-1)^2/[x(x+1)(x-1)]*1/(1-x)
=-1/[x(x+1)]
=-1/[(根号2-1)(根号2-1+1)]
=-1/[(根号2-1)*根号2]
=-1-根2/2

{(x的三次方-x)分之(x的平方-2x+1)}*(1-x分之1)
=【(x-1)^2/[x(x+1)(x-1)]】*(x-1)/x
=[(x-1)/[x(x+1)]]*(x-1)/x
=(x-1)^2/[x^2(x+1)]
=(根号2-2)²/【(根号2-1)²*根号2】
=(6-4根号2)/(3根号2-4)
=根号2.
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