function

f(x)f(1/x)=f(x)+f(1/x).given f(4)=65.find f(6)

4 Answers

Is f specified to be a polynomial. If yes, the f(x)=x³+1. As such f(6)=217.

for the given equation to be satisfied , f(x) must satisfy:
f(x) =(Â±)xⁿ+1
considering, f(4) = 65= +4³ +1

thus , f(x) =+x³+1
...........f(6)= 6³+1 = 217

organic..

i have seen a lot of such arguements in even good books..

but have not seen any convincing arguement to prove that it is x^n+1

Be careful when you are using this result (not to mean that the result is wrong :P)

341

Hari Shankar ·2009-08-13 22:33:26

The proof was one of my first posts in this forum. I am unable to retrieve the post in this forum, so i'll link to goiit:

http://www.goiit.com/posts/list/differenciation-f-x-72814.htm#358923

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