If α, β, γ and δ are the roots of x4+2x3+3x2+4x+5=0.
Find the equation whose roots are 1α,1β,1γ,1δ.
5x4+4x3+3x2+2x+1=0
Given: x4+2x3+2x2+4x+5=0 ...(1) have roots as α, β, γ, δ.
Changing x to 1x
⇒1x4+2x3+3x2+4x+5=0
⇒5x4+4x3+3x2+2x+1=0 ...(2)
Roots of the equation (2) being the reciprocal of the roots of the equation (1) i.e., 1α, 1β, 1γ, 1δ.
Hence the required equation is
⇒5x4+4x3+3x2+2x+1=0