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Question Number 1970 by 123456 last updated on 27/Oct/15

f : [0, + \infty) \to R

x f (x) = f [f (x)] f (x)

f (x) = ?

Answered by prakash jain last updated on 27/Oct/15

f (x) \neq 0 then f (f (x) = x

The following are also solutions

f (x) = {(k - x^{n})}^{1 / n} \Rightarrow f (f (x)) = x

f (x) = \frac{k}{x} \Rightarrow f (f (x)) = x

m o r e s o l u t i o n s w i l l a l s o b e t h e r r

Answered by Rasheed Soomro last updated on 27/Oct/15

O n e s o l u t i o n i s f (x) = x