Equation with linearly transformed roots

Find a new polynomial whose roots are linear transformations of the original roots (e.g., kα, α+k, kα+m), typically solved by direct substitution x = (y-m)/k or by using Vieta's formulas for the new roots.

35 questions · Standard +0.5

4.05b Transform equations: substitution for new roots
Sort by: Default | Easiest first | Hardest first
AQA Further Paper 2 2021 June Q5
5 marks Standard +0.3
5 The equation $$z ^ { 3 } + 2 z ^ { 2 } - 5 z - 3 = 0$$ has roots \(\alpha , \beta\) and \(\gamma\) Find a cubic equation with roots $$\frac { 1 } { 2 } \alpha - 1 , \frac { 1 } { 2 } \beta - 1 \text { and } \frac { 1 } { 2 } \gamma - 1$$
OCR FP1 AS 2021 June Q1
3 marks Standard +0.3
1 In this question you must show detailed reasoning.
The cubic equation \(2 x ^ { 3 } + 3 x ^ { 2 } - 5 x + 4 = 0\) has roots \(\alpha , \beta\) and \(\gamma\). By making an appropriate substitution, or otherwise, find a cubic equation with integer coefficients whose roots are \(\frac { 1 } { \alpha } , \frac { 1 } { \beta }\) and \(\frac { 1 } { \gamma }\).
OCR MEI FP1 2007 June Q5
6 marks Standard +0.3
The roots of the cubic equation \(x^3 + 3x^2 - 7x + 1 = 0\) are \(\alpha\), \(\beta\) and \(\gamma\). Find the cubic equation whose roots are \(3\alpha\), \(3\beta\) and \(3\gamma\), expressing your answer in a form with integer coefficients. [6]
AQA Further AS Paper 1 2019 June Q14
7 marks Standard +0.8
The graph of \(y = x^3 - 3x\) is shown below. \includegraphics{figure_14} The two stationary points have \(x\)-coordinates of \(-1\) and \(1\) The cubic equation $$x^3 - 3x + p = 0$$ where \(p\) is a real constant, has the roots \(\alpha\), \(\beta\) and \(\gamma\). The roots \(\alpha\) and \(\beta\) are not real.
  1. Explain why \(\alpha + \beta = -\gamma\) [1 mark]
  2. Find the set of possible values for the real constant \(p\). [2 marks]
  3. \(f(x) = 0\) is a cubic equation with roots \(\alpha + 1\), \(\beta + 1\) and \(\gamma + 1\)
    1. Show that the constant term of \(f(x)\) is \(p + 2\) [3 marks]
    2. Write down the \(x\)-coordinates of the stationary points of \(y = f(x)\) [1 mark]
AQA Further Paper 2 2024 June Q6
3 marks Moderate -0.3
The cubic equation $$x^3 + 5x^2 - 4x + 2 = 0$$ has roots \(\alpha\), \(\beta\) and \(\gamma\) Find a cubic equation, with integer coefficients, whose roots are \(3\alpha\), \(3\beta\) and \(3\gamma\) [3 marks]
Edexcel CP1 2021 June Q3
6 marks Standard +0.8
The cubic equation $$ax^3 + bx^2 - 19x - b = 0$$ where \(a\) and \(b\) are constants, has roots \(\alpha\), \(\beta\) and \(\gamma\) The cubic equation $$w^3 - 9w^2 - 97w + c = 0$$ where \(c\) is a constant, has roots \((4\alpha - 1)\), \((4\beta - 1)\) and \((4\gamma - 1)\) Without solving either cubic equation, determine the value of \(a\), the value of \(b\) and the value of \(c\). [6]
OCR Further Pure Core AS 2020 November Q5
7 marks Challenging +1.8
In this question you must show detailed reasoning. The cubic equation \(5x^3 + 3x^2 - 4x + 7 = 0\) has roots \(\alpha\), \(\beta\) and \(\gamma\). Find a cubic equation with integer coefficients whose roots are \(\alpha + \beta\), \(\beta + \gamma\) and \(\gamma + \alpha\). [7]
SPS SPS FM Pure 2023 February Q8
6 marks Challenging +1.8
The cubic equation $$ax^3 + bx^2 - 19x - b = 0$$ where \(a\) and \(b\) are constants, has roots \(\alpha\), \(\beta\) and \(\gamma\) The cubic equation $$w^3 - 9w^2 - 97w + c = 0$$ where \(c\) is a constant, has roots \((4\alpha - 1)\), \((4\beta - 1)\) and \((4\gamma - 1)\) Without solving either cubic equation, determine the value of \(a\), the value of \(b\) and the value of \(c\). [6]
SPS SPS FM Pure 2023 November Q3
8 marks Standard +0.8
In this question you must show detailed reasoning. The roots of the equation \(2x^3 - 5x + 7 = 0\) are \(\alpha\), \(\beta\) and \(\gamma\).
  1. Find \(\frac{1}{\alpha} + \frac{1}{\beta} + \frac{1}{\gamma}\). [4]
  2. Find an equation with integer coefficients whose roots are \(2\alpha - 1\), \(2\beta - 1\) and \(2\gamma - 1\). [4]
SPS SPS FM Pure 2025 February Q4
5 marks Standard +0.3
The cubic equation $$2x^3 + 6x^2 - 3x + 12 = 0$$ has roots \(\alpha\), \(\beta\) and \(\gamma\). Without solving the equation, find the cubic equation whose roots are \((\alpha + 3)\), \((\beta + 3)\) and \((\gamma + 3)\), giving your answer in the form \(pw^3 + qw^2 + rw + s = 0\), where \(p\), \(q\), \(r\) and \(s\) are integers to be found. [5]