If f(x)=4x3+3x2+3x+4,then x3f(1/x)
f(-x)
1/f(x)
f(1x)2
f(x)
we have
f(x)=4x3+3x2+3x+4
⇒f1x=4x3+3x2+3x+4 ⇒x3f(1x)=x3(4x3+3x2+3x+4) =4+3x+3x2+4x3 ∴x3f(1x)=f(x)