Edexcel Paper 2 2020 October — Question 11 7 marks

Exam BoardEdexcel
ModulePaper 2 (Paper 2)
Year2020
SessionOctober
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicModulus function
TypeGraph y=a|bx+c|+d given: solve equation or inequality
DifficultyStandard +0.3 This is a straightforward modulus function question requiring: (a) identifying the vertex by inspection, (b) solving a linear-modulus equation by cases (standard technique), and (c) finding tangent gradients using basic calculus or geometry. All parts use routine methods with no novel insight required, making it slightly easier than average.
Spec1.02l Modulus function: notation, relations, equations and inequalities1.02s Modulus graphs: sketch graph of |ax+b|1.02t Solve modulus equations: graphically with modulus function

11. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{e28350e9-5090-4079-97da-e669ef9a5a7a-30_677_817_251_621} \captionsetup{labelformat=empty} \caption{Figure 2}
\end{figure} Figure 2 shows a sketch of the graph with equation $$y = 2 | x + 4 | - 5$$ The vertex of the graph is at the point \(P\), shown in Figure 2.
  1. Find the coordinates of \(P\).
  2. Solve the equation $$3 x + 40 = 2 | x + 4 | - 5$$ A line \(l\) has equation \(y = a x\), where \(a\) is a constant.
    Given that \(l\) intersects \(y = 2 | x + 4 | - 5\) at least once,
  3. find the range of possible values of \(a\), writing your answer in set notation.

Question 11:
Part (a):
AnswerMarks Guidance
WorkingMark Guidance
\(x=-4\) or \(y=-5\)B1 1.1b - One correct coordinate
\(P(-4,-5)\)B1 2.2a - Deduces correct point
Part (b):
AnswerMarks Guidance
WorkingMark Guidance
\(3x+40=-2(x+4)-5 \Rightarrow x=...\)M1 1.1b - Attempts to solve, must reach value for \(x\)
\(x=-10.6\)A1 2.1
Part (c):
AnswerMarks Guidance
WorkingMark Guidance
\(a>2\)B1 2.2a - Deduces \(a>2\)
\(y=ax \Rightarrow -5=-4a \Rightarrow a=\frac{5}{4}\)M1 3.1a - Attempts to find value of \(a\) using \(P(-4,-5)\)
\(\{a: a\leqslant 1.25\} \cup \{a: a>2\}\)A1 2.5 - Correct range in acceptable set notation
# Question 11:

## Part (a):
| Working | Mark | Guidance |
|---------|------|----------|
| $x=-4$ **or** $y=-5$ | B1 | 1.1b - One correct coordinate |
| $P(-4,-5)$ | B1 | 2.2a - Deduces correct point |

## Part (b):
| Working | Mark | Guidance |
|---------|------|----------|
| $3x+40=-2(x+4)-5 \Rightarrow x=...$ | M1 | 1.1b - Attempts to solve, must reach value for $x$ |
| $x=-10.6$ | A1 | 2.1 |

## Part (c):
| Working | Mark | Guidance |
|---------|------|----------|
| $a>2$ | B1 | 2.2a - Deduces $a>2$ |
| $y=ax \Rightarrow -5=-4a \Rightarrow a=\frac{5}{4}$ | M1 | 3.1a - Attempts to find value of $a$ using $P(-4,-5)$ |
| $\{a: a\leqslant 1.25\} \cup \{a: a>2\}$ | A1 | 2.5 - Correct range in acceptable set notation |

---
11.

\begin{figure}[h]
\begin{center}
  \includegraphics[alt={},max width=\textwidth]{e28350e9-5090-4079-97da-e669ef9a5a7a-30_677_817_251_621}
\captionsetup{labelformat=empty}
\caption{Figure 2}
\end{center}
\end{figure}

Figure 2 shows a sketch of the graph with equation

$$y = 2 | x + 4 | - 5$$

The vertex of the graph is at the point $P$, shown in Figure 2.
\begin{enumerate}[label=(\alph*)]
\item Find the coordinates of $P$.
\item Solve the equation

$$3 x + 40 = 2 | x + 4 | - 5$$

A line $l$ has equation $y = a x$, where $a$ is a constant.\\
Given that $l$ intersects $y = 2 | x + 4 | - 5$ at least once,
\item find the range of possible values of $a$, writing your answer in set notation.
\end{enumerate}

\hfill \mbox{\textit{Edexcel Paper 2 2020 Q11 [7]}}