SPS SPS FM 2024 October — Question 4 11 marks

Exam BoardSPS
ModuleSPS FM (SPS FM)
Year2024
SessionOctober
Marks11
TopicComposite & Inverse Functions
TypeState domain or range
DifficultyModerate -0.3 This is a straightforward multi-part question on functions covering standard techniques: completing the square for range, understanding inverse existence, function composition, and solving a quadratic inequality. All parts are routine A-level procedures with no novel problem-solving required, making it slightly easier than average but not trivial due to the multiple components.
Spec1.02g Inequalities: linear and quadratic in single variable1.02v Inverse and composite functions: graphs and conditions for existence

The functions f and g are defined for all real values of \(x\) by \(f(x) = 2x^2 + 6x\) and \(g(x) = 3x + 2\).
  1. Find the range of f. [3]
  2. Give a reason why f has no inverse. [1]
  3. Given that \(fg(-2) = g^{-1}(a)\), where \(a\) is a constant, determine the value of \(a\). [4]
  4. Determine the set of values of \(x\) for which \(f(x) > g(x)\). Give your answer in set notation. [3]

The functions f and g are defined for all real values of $x$ by

$f(x) = 2x^2 + 6x$ and $g(x) = 3x + 2$.

\begin{enumerate}[label=(\alph*)]
\item Find the range of f. [3]

\item Give a reason why f has no inverse. [1]

\item Given that $fg(-2) = g^{-1}(a)$, where $a$ is a constant, determine the value of $a$. [4]

\item Determine the set of values of $x$ for which $f(x) > g(x)$. Give your answer in set notation. [3]
\end{enumerate}

\hfill \mbox{\textit{SPS SPS FM 2024 Q4 [11]}}