SPS SPS FM 2024 October — Question 1 8 marks

Exam BoardSPS
ModuleSPS FM (SPS FM)
Year2024
SessionOctober
Marks8
TopicIndices and Surds
TypeSolve exponential equations
DifficultyModerate -0.8 This question tests routine algebraic manipulation skills. Part (a)(i) involves standard rationalization of surds with common denominators, part (a)(ii) is a straightforward linear equation after simplification, and part (b) is a standard exponential equation solved by substitution (let y = 2^x). All techniques are textbook exercises requiring recall and careful algebra but no problem-solving insight or novel approaches.
Spec1.02b Surds: manipulation and rationalising denominators1.06g Equations with exponentials: solve a^x = b

    1. Show that \(\frac{1}{3-2\sqrt{x}} + \frac{1}{3+2\sqrt{x}}\) can be written in the form \(\frac{a}{b+cx}\), where \(a\), \(b\) and \(c\) are constants to be determined. [2]
    2. Hence solve the equation \(\frac{1}{3-2\sqrt{x}} + \frac{1}{3+2\sqrt{x}} = 2\). [2]
  1. In this question you must show detailed reasoning. Solve the equation \(2^{2x} - 7 \times 2^x - 8 = 0\). [4]

\begin{enumerate}[label=(\alph*)]
\item 
\begin{enumerate}[label=(\roman*)]
\item Show that $\frac{1}{3-2\sqrt{x}} + \frac{1}{3+2\sqrt{x}}$ can be written in the form $\frac{a}{b+cx}$, where $a$, $b$ and $c$ are constants to be determined. [2]

\item Hence solve the equation $\frac{1}{3-2\sqrt{x}} + \frac{1}{3+2\sqrt{x}} = 2$. [2]
\end{enumerate}

\item In this question you must show detailed reasoning.

Solve the equation $2^{2x} - 7 \times 2^x - 8 = 0$. [4]
\end{enumerate}

\hfill \mbox{\textit{SPS SPS FM 2024 Q1 [8]}}