Solve $f(x)f(2x^2) = f(2x^3+x)$
117353
Polynomial equation $f(x)f(2x^2)=f(2x^3+x)$
155806
(Olympiad Question) $f(2x) + 2f(y) = f(f(x+y))$
122329
Determine all functions $f(x)$ such that $f(f(x+y))=f(x)+f(y)$
158933
Rational solutions of $y^2 = x^3 - x$
147325
Proving that if $f(x)=x$ has no real solution then $f(f(x))=x$ has no real solution either
63750
let $f(\frac{x}{3})+f(\frac{2}{x})=\frac{4}{x^2}+\frac{x^2}{9}-2$ then find $f(x)$
141223
$f(x^2) = 2f(x)$ and $f(x)$ continuous
98255
Find $f(x)$ such that $f(f(x)) = x^2 - 2$
52858
Find $f$ if $ f(x)+f\left(\frac{1}{1-x}\right)=x $
59063
$f(f(x))=f(x)$ question
131692
How to show that $f_{0}f_{1}+f_{1}f_{2}+...+f_{2n-1}f_{2n} = f^{2}_{2n}$
72769
How find this function $xf(x^2)=f(x),x>0$
149254
Solving $y^3=x^3+8x^2-6x+8$
153942
Solution of functional equation $f(x+y)=f(x)+f(y)+y\sqrt{f(x)}$
69734
how to find all functions such that $f\left( x^{2} - y^{2} \right) = ( x - y )( f(x) + f(y) )$
17175
Problem in solving functional equation $f(x^2 + yf(x)) = xf(x+y)$
151519
If $f(f(x))=x^2-x+1$, what is $f(0)$?