OCR MEI C1 — Question 12 12 marks

Exam BoardOCR MEI
ModuleC1 (Core Mathematics 1)
Marks12
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicCompleting the square and sketching
TypeLine-curve intersection points
DifficultyModerate -0.3 This is a straightforward C1 question testing standard techniques: completing the square to show no real roots, solving a quadratic inequality, and finding intersection points. All three parts use routine methods with no novel insight required, though part (iii) involves slightly more algebraic manipulation than typical. Slightly easier than average due to the mechanical nature of the tasks.
Spec1.02d Quadratic functions: graphs and discriminant conditions1.02g Inequalities: linear and quadratic in single variable

  1. Show that the graph of \(y = x^2 - 3x + 11\) is above the \(x\)-axis for all values of \(x\). [3]
  2. Find the set of values of \(x\) for which the graph of \(y = 2x^2 + x - 10\) is above the \(x\)-axis. [4]
  3. Find algebraically the coordinates of the points of intersection of the graphs of $$y = x^2 - 3x + 11 \quad\text{and}\quad y = 2x^2 + x - 10.$$ [5]

\begin{enumerate}[label=(\roman*)]
\item Show that the graph of $y = x^2 - 3x + 11$ is above the $x$-axis for all values of $x$. [3]

\item Find the set of values of $x$ for which the graph of $y = 2x^2 + x - 10$ is above the $x$-axis. [4]

\item Find algebraically the coordinates of the points of intersection of the graphs of
$$y = x^2 - 3x + 11 \quad\text{and}\quad y = 2x^2 + x - 10.$$ [5]
\end{enumerate}

\hfill \mbox{\textit{OCR MEI C1  Q12 [12]}}