SPS SPS FM 2024 November — Question 2 10 marks

Exam BoardSPS
ModuleSPS FM (SPS FM)
Year2024
SessionNovember
Marks10
TopicHyperbolic functions
TypeProve inverse hyperbolic logarithmic form
DifficultyStandard +0.8 This is a standard Further Maths proof of an inverse hyperbolic function's logarithmic form, requiring manipulation of exponentials and logarithms, followed by a non-routine application requiring substitution and algebraic manipulation. The proof itself is bookwork, but part (b) requires insight to apply the result and handle the domain restrictions carefully.
Spec4.07e Inverse hyperbolic: definitions, domains, ranges4.07f Inverse hyperbolic: logarithmic forms

2.
  1. Prove that $$\tanh ^ { - 1 } ( x ) = \frac { 1 } { 2 } \ln \left( \frac { 1 + x } { 1 - x } \right) \quad - k < x < k$$ stating the value of the constant \(k\).
  2. Hence, or otherwise, solve the equation $$2 x = \tanh ( \ln \sqrt { 2 - 3 x } )$$

2.\\
\begin{enumerate}[label=(\alph*)]
\item Prove that

$$\tanh ^ { - 1 } ( x ) = \frac { 1 } { 2 } \ln \left( \frac { 1 + x } { 1 - x } \right) \quad - k < x < k$$

stating the value of the constant $k$.
\item Hence, or otherwise, solve the equation

$$2 x = \tanh ( \ln \sqrt { 2 - 3 x } )$$

\\
\end{enumerate}

\hfill \mbox{\textit{SPS SPS FM 2024 Q2 [10]}}