Edexcel FP2 — Question 6 12 marks

Exam BoardEdexcel
ModuleFP2 (Further Pure Mathematics 2)
Marks12
PaperDownload PDF ↗
TopicInequalities
TypeSolve absolute value inequality
DifficultyStandard +0.8 This FP2 question requires systematic case analysis of the absolute value equation (considering both positive and negative cases), careful algebraic manipulation to solve resulting quadratics, validation of solutions against domain restrictions, sketching with critical points, and translating graphical understanding to solve the inequality. While methodical, it demands multiple techniques and careful reasoning about when solutions are valid, placing it moderately above average difficulty.
Spec1.02l Modulus function: notation, relations, equations and inequalities1.02t Solve modulus equations: graphically with modulus function

  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]

\begin{enumerate}[label=(\alph*)]
\item Use algebra to find the exact solutions of the equation
$$|2x^2 + 6x - 5| = 5 - 2x$$ [6]
\item 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]
\item Find the set of values of $x$ for which
$$|2x^2 + 6x - 5| > 5 - 2x$$ [3]
\end{enumerate}

\hfill \mbox{\textit{Edexcel FP2  Q6 [12]}}