Edexcel F1 2016 January — Question 3

Exam BoardEdexcel
ModuleF1 (Further Pure Mathematics 1)
Year2016
SessionJanuary
TopicRoots of polynomials

3. The quadratic equation $$x ^ { 2 } - 2 x + 3 = 0$$ has roots \(\alpha\) and \(\beta\).
Without solving the equation,
    1. write down the value of \(( \alpha + \beta )\) and the value of \(\alpha \beta\)
    2. show that \(\alpha ^ { 2 } + \beta ^ { 2 } = - 2\)
    3. find the value of \(\alpha ^ { 3 } + \beta ^ { 3 }\)
    1. show that \(\alpha ^ { 4 } + \beta ^ { 4 } = \left( \alpha ^ { 2 } + \beta ^ { 2 } \right) ^ { 2 } - 2 ( \alpha \beta ) ^ { 2 }\)
    2. find a quadratic equation which has roots $$\text { ( } \alpha ^ { 3 } - \beta \text { ) and ( } \beta ^ { 3 } - \alpha \text { ) }$$ giving your answer in the form \(p x ^ { 2 } + q x + r = 0\) where \(p , q\) and \(r\) are integers.