If the roots of the equation ax2+bx+c=0 beα and β,, then the roots of the equation cx2+bx+a=0 are
α,β are roots of ax2+bx+c=0
⇒ α+β= −ba and αβ=ca
Let the roots of cx2+bx+a=0 be α',β', then
α ' + β '=−bc and α β=ac
but α+βαβ=−baca=−bc1α+1β=α′+β′
Hence α′=1α and β′=1β