Edexcel C1 — Question 19 14 marks

Exam BoardEdexcel
ModuleC1 (Core Mathematics 1)
Marks14
PaperDownload PDF ↗
TopicCurve Sketching
TypeVertex form already given
DifficultyEasy -1.2 This C1 question involves straightforward tasks: identifying the maximum of a parabola in completed square form (immediate from inspection), sketching a quadratic (routine), finding a line equation through two given points (standard formula application), finding x-intercept (simple substitution), and finding k from a midpoint condition (basic coordinate geometry). All parts are direct applications of standard techniques with no problem-solving or insight required, making it easier than average.
Spec1.02n Sketch curves: simple equations including polynomials1.03a Straight lines: equation forms y=mx+c, ax+by+c=0

\(f(x) = 9 - (x - 2)^2\)
  1. Write down the maximum value of \(f(x)\). [1]
  2. Sketch the graph of \(y = f(x)\), showing the coordinates of the points at which the graph meets the coordinate axes. [5]
The points \(A\) and \(B\) on the graph of \(y = f(x)\) have coordinates \((-2, -7)\) and \((3, 8)\) respectively.
  1. Find, in the form \(y = mx + c\), an equation of the straight line through \(A\) and \(B\). [4]
  2. Find the coordinates of the point at which the line \(AB\) crosses the \(x\)-axis. [2]
The mid-point of \(AB\) lies on the line with equation \(y = kx\), where \(k\) is a constant.
  1. Find the value of \(k\). [2]

$f(x) = 9 - (x - 2)^2$

\begin{enumerate}[label=(\alph*)]
\item Write down the maximum value of $f(x)$. [1]
\item Sketch the graph of $y = f(x)$, showing the coordinates of the points at which the graph meets the coordinate axes. [5]
\end{enumerate}

The points $A$ and $B$ on the graph of $y = f(x)$ have coordinates $(-2, -7)$ and $(3, 8)$ respectively.

\begin{enumerate}[label=(\alph*)]
\setcounter{enumi}{2}
\item Find, in the form $y = mx + c$, an equation of the straight line through $A$ and $B$. [4]
\item Find the coordinates of the point at which the line $AB$ crosses the $x$-axis. [2]
\end{enumerate}

The mid-point of $AB$ lies on the line with equation $y = kx$, where $k$ is a constant.

\begin{enumerate}[label=(\alph*)]
\setcounter{enumi}{4}
\item Find the value of $k$. [2]
\end{enumerate}

\hfill \mbox{\textit{Edexcel C1  Q19 [14]}}