f(x-1/x)=x^3-1/x^3 则f(x)的解析式为?

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f(x-1/x)=x^3-1/x^3 则f(x)的解析式为?
f(x-1/x)=x^3-1/x^3 则f(x)的解析式为?

f(x-1/x)=x^3-1/x^3 则f(x)的解析式为?
f(x-1/x)=x^3-1/x^3
=(x-1/x)(x^2+1/x^2+1)
=(x-1/x)[(x^2+1/x^2-2)+3]
=(x-1/x)[(x-1/x)^2+3]
则设x-1/x=T
则f(T)=T*(T^2+3)
=T^3+3T
则f(x)=x^3+3x

x^3什么意思啊???X的三次幂???就当它算了,不是的话,你自己带
设X-1\X=t
则X-1\X可化为1-1\X=t
则1\X=1-t
把t带进x^3-1/x^3
可得f(t)=....
把t换成X即可

f(x-1/x)=x^3-1/x^3
=(x-1/x)(x^2+1/x^2+1)
=(x-1/x)(x^2+1/x^2-2+3)
=(x-1/x)((x-1/x)^2+3)
令x-1/x=t,于是
f(t)=t(t^2+3)
f(x)=x(x^2+3)