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A positive rational function (Posted on 2019-11-01)

Let Q' denote the set of all positive rational numbers. If f:Q'→Q' satisfies

f(x²f(y)²)=f(x)²f(y),

evaluate f(2019).

No Solution Yet Submitted by Danish Ahmed Khan

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re: one solution

| Comment 2 of 3 |

(In reply to one solution by Daniel)

f(x)=0 works likewise. Whoops! 0 is not positive - so nothing maps into Q'. Nevermind.

Edited on November 1, 2019, 11:30 am

Posted by Steven Lord on 2019-11-01 11:25:51

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