AQA C1 2010 June — Question 7

Exam BoardAQA
ModuleC1 (Core Mathematics 1)
Year2010
SessionJune
TopicQuadratic Functions

7
    1. Express \(2 x ^ { 2 } - 20 x + 53\) in the form \(2 ( x - p ) ^ { 2 } + q\), where \(p\) and \(q\) are integers.
    2. Use your result from part (a)(i) to explain why the equation \(2 x ^ { 2 } - 20 x + 53 = 0\) has no real roots.
  1. The quadratic equation \(( 2 k - 1 ) x ^ { 2 } + ( k + 1 ) x + k = 0\) has real roots.
    1. Show that \(7 k ^ { 2 } - 6 k - 1 \leqslant 0\).
    2. Hence find the possible values of \(k\).