Reciprocal sum of roots

A question is this type if and only if it asks to find expressions like 1/α + 1/β + 1/γ or 1/α² + 1/β² + 1/γ² using relationships between roots and coefficients.

5 questions · Standard +0.1

4.05a Roots and coefficients: symmetric functions
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Edexcel F1 2017 June Q1
4 marks Moderate -0.8
  1. The quadratic equation
$$3 x ^ { 2 } - 5 x + 1 = 0$$ has roots \(\alpha\) and \(\beta\).
Without solving the quadratic equation, find the exact value of $$\frac { \alpha } { \beta } + \frac { \beta } { \alpha }$$
Count coution \(\_\_\_\_\) T
OCR FP1 2009 June Q4
4 marks Moderate -0.5
4 The roots of the quadratic equation \(x ^ { 2 } + x - 8 = 0\) are \(p\) and \(q\). Find the value of \(p + q + \frac { 1 } { p } + \frac { 1 } { q }\).
OCR Further Pure Core AS 2023 June Q5
4 marks Moderate -0.3
5 In this question you must show detailed reasoning. The roots of the equation \(5 x ^ { 2 } - 3 x + 12 = 0\) are \(\alpha\) and \(\beta\). By considering the symmetric functions of the roots, \(\alpha + \beta\) and \(\alpha \beta\), determine the exact value of \(\frac { 1 } { \alpha ^ { 2 } } + \frac { 1 } { \beta ^ { 2 } }\).
SPS SPS FM Pure 2026 November Q10
8 marks Challenging +1.2
The quartic equation $$2x^4 + Ax^3 - Ax^2 - 5x + 6 = 0$$ where \(A\) is a real constant, has roots \(\alpha\), \(\beta\), \(\gamma\) and \(\delta\)
  1. Determine the value of $$\frac{3}{\alpha} + \frac{3}{\beta} + \frac{3}{\gamma} + \frac{3}{\delta}$$ [3]
Given that \(\alpha^2 + \beta^2 + \gamma^2 + \delta^2 = -\frac{3}{4}\)
  1. determine the possible values of \(A\) [5]
OCR Further Pure Core 2 2018 March Q4
4 marks Standard +0.8
You are given that the cubic equation \(2x^3 - 3x^2 + x + 4 = 0\) has three roots, \(\alpha\), \(\beta\) and \(\gamma\). By making a suitable substitution to obtain a related cubic equation, determine the value of \(\frac{1}{\alpha} + \frac{1}{\beta} + \frac{1}{\gamma}\). [4]