Edexcel C2 — Question 2

Exam BoardEdexcel
ModuleC2 (Core Mathematics 2)
TopicFactor & Remainder Theorem
TypePolynomial identity or expansion

2. $$f ( n ) = n ^ { 3 } + p n ^ { 2 } + 11 n + 9 , \text { where } p \text { is a constant. }$$
  1. Given that \(\mathrm { f } ( n )\) has a remainder of 3 when it is divided by ( \(n + 2\) ), prove that \(p = 6\).
  2. Show that \(\mathrm { f } ( n )\) can be written in the form \(( n + 2 ) ( n + q ) ( n + r ) + 3\), where \(q\) and \(r\) are integers to be found.
  3. Hence show that \(\mathrm { f } ( n )\) is divisible by 3 for all positive integer values of \(n\).