Factor condition (zero remainder)

Questions where a linear expression is stated to be a factor of the polynomial, requiring the polynomial to equal zero at a specific value.

4 questions · Easy -1.0

1.02j Manipulate polynomials: expanding, factorising, division, factor theorem
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OCR MEI C1 Q11
12 marks Moderate -0.8
11 In this question \(\mathrm { f } ( x ) = x ^ { 3 } - 2 x ^ { 2 } - 4 x + k\).
  1. You are asked to find the values of \(k\) which satisfy the following conditions.
    (A) The graph of \(y = \mathrm { f } ( x )\) goes through the origin.
    (B) The graph of \(y = \mathrm { f } ( x )\) intersects with the \(y\) axis at ( \(0 , - 2\) ).
    (C) ( \(x - 2\) ) is a factor of \(\mathrm { f } ( x )\).
    (D) The remainder when \(\mathrm { f } ( x )\) is divided by \(( x + 1 )\) is 5 .
    (E) The graph of \(y = \mathrm { f } ( x )\) is as shown in the diagram below. \includegraphics[max width=\textwidth, alt={}, center]{3b6291ef-bef9-49de-a20f-591e621bed65-3_373_788_2131_584}
  2. Find the solution of the equation \(\mathrm { f } ( x ) = 0\) when \(k = 8\). Sketch a graph of \(y = \mathrm { f } ( x )\) in this case.
OCR MEI Paper 1 2018 June Q1
3 marks Easy -1.8
1 Show that ( \(x - 2\) ) is a factor of \(3 x ^ { 3 } - 8 x ^ { 2 } + 3 x + 2\).
AQA Paper 1 2022 June Q11
10 marks Moderate -0.3
11 The polynomial \(\mathrm { p } ( x )\) is given by $$\mathrm { p } ( x ) = x ^ { 3 } + ( b + 2 ) x ^ { 2 } + 2 ( b + 2 ) x + 8$$ where \(b\) is a constant.
11
  1. Use the factor theorem to prove that \(( x + 2 )\) is a factor of \(\mathrm { p } ( x )\) for all values of \(b\).
    11
  2. The graph of \(y = \mathrm { p } ( x )\) meets the \(x\)-axis at exactly two points.
    11 (b) (i) Sketch a possible graph of \(y = \mathrm { p } ( x )\) \includegraphics[max width=\textwidth, alt={}, center]{22ff390e-1360-43bd-8c7f-3d2b58627e91-20_1084_965_1619_532} 11 (b) (ii) Given \(\mathrm { p } ( x )\) can be written as $$\mathrm { p } ( x ) = ( x + 2 ) \left( x ^ { 2 } + b x + 4 \right)$$ find the value of \(b\). Fully justify your answer.
AQA AS Paper 1 2024 June Q5
3 marks Easy -1.2
A student is looking for factors of the polynomial \(f(x)\) They suggest that \((x - 2)\) is a factor of \(f(x)\) The method they use to check this suggestion is to calculate \(f(-2)\) They correctly calculate that \(f(-2) = 0\) They conclude that their suggestion is correct.
  1. Make one comment about the student's method. [1 mark]
  2. Make two comments about the student's conclusion. [2 marks] 1 2