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问题: 2.(1)f(x)=(x^2+x+1)(x^2-x+1)(x^2-1)

2.(1)f(x)=(x^2+x+1)(x^2-x+1)(x^2-1)
(2)f(x)=(x+1)^2*(x-1)^2+2x^2
证明:
(1)==〉f[2^(1/6)]=1
(2)=/=〉f[2^(1/6)]=1

解答:

2.解:
(1)原式=(x^2+x+1)(x^2-x+1)(x+1)(x-1)
=[(x-1)(x^2+x+1)][(x+1)(x^2-x+1)]
=(x^3-1)(x^3+1)
=x^6-1
故f[2^(1/6)]=2-1=1.
(2)原式 =[(x+1)(x-1)]^2+2x^2
=(x^2-1)^2+2x^2
=x^4-2x^2+1+2x^2
=x^4+1
故f[2^(1/6)]=[2^(1/6)]^4+1=2^(2/3)+1>1
即f[2^(1/6)]≠1