9231 P13 - Jun 2013 - Q2
6398
The roots of the equation \(x^{4}-4 x^{2}+3 x-2=0\) are \(\alpha, \beta, \gamma\) and \(\delta\); the sum \(\alpha^{n}+\beta^{n}+\gamma^{n}+\delta^{n}\) is denoted by \(S_{n}\). By using the relation \(y=x^{2}\), or otherwise, show that \(\alpha^{2}, \beta^{2}, \gamma^{2}\) and \(\delta^{2}\) are the roots of the equation
\(y^{4}-8 y^{3}+12 y^{2}+7 y+4=0\)
State the value of \(S_{2}\) and hence show that
\(S_{8}=8 S_{6}-12 S_{4}-72 .\)
