antwnis
contestada

if
[tex]f(x) = 3x {}^{3} + x[/tex] And
[tex]f( - x) = - f(x)[/tex]
Solve the inequality :
[tex]f(2 {}^{f(x)} ) + f(f(x) - 20) < f( ln(e {}^{ - x} + 1) ) + f(x - ln(e {}^{x} + 1 ) )[/tex]