Edexcel C1 Specimen — Question 3 4 marks

Exam BoardEdexcel
ModuleC1 (Core Mathematics 1)
SessionSpecimen
Marks4
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicIndices and Surds
TypeExpand and simplify surd expressions
DifficultyEasy -1.3 This is a straightforward C1 question testing basic surd manipulation. Part (a) requires simple factorization of 80 and extracting square roots. Part (b) involves expanding a binomial with a surd, which is routine practice requiring only careful arithmetic. Both parts are standard textbook exercises with no problem-solving element, making this easier than average.
Spec1.02b Surds: manipulation and rationalising denominators

  1. Express \(\sqrt{80}\) in the form \(a\sqrt{5}\), where \(a\) is an integer. [1]
  2. Express \((4 - \sqrt{5})^2\) in the form \(b + c\sqrt{5}\), where \(b\) and \(c\) are integers. [3]

\begin{enumerate}[label=(\alph*)]
\item Express $\sqrt{80}$ in the form $a\sqrt{5}$, where $a$ is an integer. [1]
\item Express $(4 - \sqrt{5})^2$ in the form $b + c\sqrt{5}$, where $b$ and $c$ are integers. [3]
\end{enumerate}

\hfill \mbox{\textit{Edexcel C1  Q3 [4]}}