Edexcel C1 2018 June — Question 3

Exam BoardEdexcel
ModuleC1 (Core Mathematics 1)
Year2018
SessionJune
TopicQuadratic Functions

3. $$f ( x ) = x ^ { 2 } - 10 x + 23$$
  1. Express \(\mathrm { f } ( x )\) in the form \(( x + a ) ^ { 2 } + b\), where \(a\) and \(b\) are constants to be found.
  2. Hence, or otherwise, find the exact solutions to the equation $$x ^ { 2 } - 10 x + 23 = 0$$
  3. Use your answer to part (b) to find the larger solution to the equation $$y - 10 y ^ { 0.5 } + 23 = 0$$ Write your solution in the form \(p + q \sqrt { r }\), where \(p , q\) and \(r\) are integers.