1.26: Past-paper question 5

4PM1/1/June/2025 — Question 5 · 8 marks

(a) Show that (α+β)33αβ(α+β)=α3+β3\displaystyle (\alpha + \beta)^3 - 3\alpha\beta(\alpha + \beta) = \alpha^3 + \beta^3
(2)
The quadratic equation 2x26x7=0\displaystyle 2x^2 - 6x - 7 = 0 has roots α\displaystyle \alpha and β\displaystyle \beta
Without solving the equation
(b) form a quadratic equation, with integer coefficients, which has roots α2β\displaystyle \frac{\alpha^2}{\beta} and β2α\displaystyle \frac{\beta^2}{\alpha}
(6)