If the definition field of function f (x) is {x | x not = 0}, and f (x) - 2F (1 / x) = 3x, then the analytic expression of F (x) is
f(x)-2f(1/x)=3x (1)
Let x = 1 / X
f(1/x)-2f(x)=3/x (2)
(2)×2+(1)
-3f(x)=6/x+3x=3(x²+2)/x
f(x)=-(x²+2)/x
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