Edexcel P2 2022 January — Question 5

Exam BoardEdexcel
ModuleP2 (Pure Mathematics 2)
Year2022
SessionJanuary
TopicFactor & Remainder Theorem
TypePolynomial with equal remainders

5. $$f ( x ) = 3 x ^ { 3 } + A x ^ { 2 } + B x - 10$$ where \(A\) and \(B\) are integers.
Given that
  • when \(\mathrm { f } ( x )\) is divided by \(( x - 1 )\) the remainder is \(k\)
  • when \(\mathrm { f } ( x )\) is divided by \(( x + 1 )\) the remainder is \(- 10 k\)
  • \(k\) is a constant
    1. show that
$$11 A + 9 B = 83$$ Given also that \(( 3 x - 2 )\) is a factor of \(\mathrm { f } ( x )\),
  • find the value of \(A\) and the value of \(B\).
  • Hence find the quadratic expression \(\mathrm { g } ( x )\) such that $$f ( x ) = ( 3 x - 2 ) g ( x )$$