Edexcel C1 — Question 5 6 marks

Exam BoardEdexcel
ModuleC1 (Core Mathematics 1)
Marks6
PaperDownload PDF ↗
TopicIndices and Surds
TypeRationalize denominator simple
DifficultyEasy -1.2 Part (a) is a straightforward simplification of a surd requiring factorization of 45 = 9×5. Part (b) is a standard rationalizing the denominator exercise requiring multiplication by the conjugate and simplification, which is routine C1 content. Both parts are textbook exercises with no problem-solving required, making this easier than average but not trivial due to the algebraic manipulation in part (b).
Spec1.02b Surds: manipulation and rationalising denominators

  1. Write \(\sqrt{45}\) in the form \(a\sqrt{5}\), where \(a\) is an integer. [1]
  2. Express \(\frac{2(3 + \sqrt{5})}{(3 - \sqrt{5})}\) in the form \(b + c\sqrt{5}\), where \(b\) and \(c\) are integers. [5]

\begin{enumerate}[label=(\alph*)]
\item Write $\sqrt{45}$ in the form $a\sqrt{5}$, where $a$ is an integer. [1]
\item Express $\frac{2(3 + \sqrt{5})}{(3 - \sqrt{5})}$ in the form $b + c\sqrt{5}$, where $b$ and $c$ are integers. [5]
\end{enumerate}

\hfill \mbox{\textit{Edexcel C1  Q5 [6]}}