OCR FP1 2005 June — Question 8

Exam BoardOCR
ModuleFP1 (Further Pure Mathematics 1)
Year2005
SessionJune
TopicRoots of polynomials

8
  1. The quadratic equation \(x ^ { 2 } - 2 x + 4 = 0\) has roots \(\alpha\) and \(\beta\).
    1. Write down the values of \(\alpha + \beta\) and \(\alpha \beta\).
    2. Show that \(\alpha ^ { 2 } + \beta ^ { 2 } = - 4\).
    3. Hence find a quadratic equation which has roots \(\alpha ^ { 2 }\) and \(\beta ^ { 2 }\).
  2. The cubic equation \(x ^ { 3 } - 12 x ^ { 2 } + a x - 48 = 0\) has roots \(p , 2 p\) and \(3 p\).
    1. Find the value of \(p\).
    2. Hence find the value of \(a\).