Solve absolute value inequality

Solve inequalities involving absolute value expressions like |ax + b| < c or |ax + b| > |cx + d|.

23 questions · Standard +0.2

1.02l Modulus function: notation, relations, equations and inequalities
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CAIE P2 2008 June Q1
3 marks Easy -1.2
1 Solve the inequality \(| 3 x - 1 | < 2\).
CAIE P3 2002 November Q1
3 marks Easy -1.2
1 Solve the inequality \(| 9 - 2 x | < 1\).
CAIE P2 2011 November Q2
4 marks Standard +0.3
2 Solve the inequality \(| 2 x - 3 | \leqslant | 3 x |\).
CAIE P2 2018 November Q1
4 marks Standard +0.3
1 Solve the inequality \(| 3 x - 5 | < 2 | x |\).
Edexcel FP1 2020 June Q6
10 marks Challenging +1.2
  1. A physics student is studying the movement of particles in an electric field. In one experiment, the distances in micrometres of two moving particles, \(A\) and \(B\), from a fixed point \(O\) are modelled by
$$\begin{aligned} & d _ { A } = | 5 t - 31 | \\ & d _ { B } = \left| 3 t ^ { 2 } - 25 t + 8 \right| \end{aligned}$$ respectively, where \(t\) is the time in seconds after motion begins.
  1. Use algebra to find the range of time for which particle \(A\) is further away from \(O\) than particle \(B\) is from \(O\). It was recorded that the distance of particle \(B\) from \(O\) was less than the distance of particle \(A\) from \(O\) for approximately 4 seconds.
  2. Use this information to assess the validity of the model.
Edexcel FP1 2021 June Q3
8 marks Challenging +1.2
3. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{55803551-f13d-419f-8b51-31642bd20b6a-08_494_780_258_644} \captionsetup{labelformat=empty} \caption{Figure 1}
\end{figure} Figure 1 shows a sketch of the curve with equation \(y = \mathrm { f } ( x )\) where $$f ( x ) = \frac { x } { | x | - 2 }$$ Use algebra to determine the values of \(x\) for which $$2 x - 5 > \frac { x } { | x | - 2 }$$
Edexcel FP1 2022 June Q7
8 marks Challenging +1.2
7. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{7de3f581-eff1-4671-87a9-55ca1bb97890-20_591_962_312_548} \captionsetup{labelformat=empty} \caption{Figure 1}
\end{figure} Figure 1 shows a sketch of the curve with equation \(y = \left| x ^ { 2 } - 8 \right|\) and a sketch of the straight line with equation \(y = m x + c\), where \(m\) and \(c\) are positive constants. The equation $$\left| x ^ { 2 } - 8 \right| = m x + c$$ has exactly 3 roots, as shown in Figure 1.
  1. Show that $$m ^ { 2 } - 4 c + 32 = 0$$ Given that \(c = 3 m\)
  2. determine the value of \(m\) and the value of \(c\)
  3. Hence solve $$\left| x ^ { 2 } - 8 \right| \geqslant m x + c$$
Edexcel FP1 2024 June Q2
4 marks Standard +0.8
  1. Use algebra to determine the values of \(x\) for which
$$\left| x ^ { 2 } - 2 x \right| \leqslant x$$
Pre-U Pre-U 9794/1 2014 June Q3
3 marks Easy -1.2
3 Solve the inequality \(| 2 x - 1 | < 3\).
Pre-U Pre-U 9794/1 2018 June Q1
4 marks Moderate -0.3
1 Solve \(5 x + 3 < | 3 x - 1 |\).
CAIE P2 2024 June Q1
4 marks Standard +0.3
Solve the inequality \(|5x + 7| > |2x - 3|\). [4]
CAIE P2 2023 March Q4
7 marks Moderate -0.3
  1. Sketch, on the same diagram, the graphs of \(y = |2x - 1|\) and \(y = 3x - 3\). [2]
  2. Solve the inequality \(|2x - 1| < 3x - 3\). [3]
  3. Find the smallest integer \(N\) satisfying the inequality \(|2 \ln N - 1| < 3 \ln N - 3\). [2]
CAIE P2 2024 November Q2
4 marks Standard +0.3
Solve the inequality \(|x - 7| > 4x + 3\). [4]
CAIE P2 2003 November Q1
3 marks Moderate -0.8
Find the set of values of \(x\) satisfying the inequality \(|8 - 3x| < 2\). [3]
CAIE P3 2017 June Q2
4 marks Standard +0.3
Solve the inequality \(|x - 3| < 3x - 4\). [4]
Edexcel FP2 Q1
5 marks Standard +0.8
Find the set of values of \(x\) for which $$|x^2 - 4| > 3x.$$ [5]
Edexcel FP2 Q6
12 marks Standard +0.8
  1. Use algebra to find the exact solutions of the equation $$|2x^2 + 6x - 5| = 5 - 2x$$ [6]
  2. On the same diagram, sketch the curve with equation \(y = |2x^2 + 6x - 5|\) and the line with equation \(y = 5 - 2x\), showing the \(x\)-coordinates of the points where the line crosses the curve. [3]
  3. Find the set of values of \(x\) for which $$|2x^2 + 6x - 5| > 5 - 2x$$ [3]
OCR C3 Q2
5 marks Standard +0.8
Solve the inequality \(|2x - 3| < |x + 1|\). [5]
OCR C3 Q2
5 marks Standard +0.8
Solve the inequality \(|4x - 3| < |2x + 1|\). [5]
OCR C3 Q2
5 marks Standard +0.8
Find the set of values of \(x\) such that $$|3x + 1| \leq |x - 2|.$$ [5]
AQA Further Paper 2 2019 June Q3
1 marks Moderate -0.8
The set \(A\) is defined by \(A = \{x : -\sqrt{2} < x < 0\} \cup \{x : 0 < x < \sqrt{2}\}\) Which of the inequalities given below has \(A\) as its solution? Circle your answer. [1 mark] \(|x^2 - 1| > 1\) \quad\quad \(|x^2 - 1| \geq 1\) \quad\quad \(|x^2 - 1| < 1\) \quad\quad \(|x^2 - 1| \leq 1\)
AQA Further Paper 2 2024 June Q15
7 marks Standard +0.8
The diagram shows the line \(y = 5 - x\) \includegraphics{figure_15}
  1. On the diagram above, sketch the graph of \(y = |x^2 - 4x|\), including all parts of the graph where it intersects the line \(y = 5 - x\) (You do not need to show the coordinates of the points of intersection.) [3 marks]
  2. Find the solution of the inequality $$|x^2 - 4x| > 5 - x$$ Give your answer in an exact form. [4 marks]
SPS SPS FM 2019 Q5
6 marks Standard +0.3
Solve the following inequalities giving your answer in set notation:
  1. \(|4x + 3| < |x - 8|\) [3]
  2. \(\frac{x}{x^2+1} < \frac{1}{2}\) [3]