AQA AS Paper 1 2024 June — Question 3 4 marks

Exam BoardAQA
ModuleAS Paper 1 (AS Paper 1)
Year2024
SessionJune
Marks4
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicIndices and Surds
TypeRationalize denominator two surds
DifficultyModerate -0.8 This is a standard surds rationalisation question requiring multiplication by the conjugate and simplification. While it involves multiple algebraic steps and careful arithmetic, it's a routine technique taught early in AS-level with no problem-solving insight required—just methodical application of (a+b)(a-b)=a²-b² and collecting like terms. The 4 marks reflect working rather than conceptual difficulty.
Spec1.02b Surds: manipulation and rationalising denominators

Express \(\frac{\sqrt{3} + 3\sqrt{5}}{\sqrt{5} - \sqrt{3}}\) in the form \(a + b\sqrt{c}\), where \(a\) and \(b\) are integers. Fully justify your answer. [4 marks]

Question 3:
AnswerMarks
3Multiplies numerator and
denominator by conjugate of the
denominator
AnswerMarks Guidance
Condone missing brackets1.1b B1
×
5− 3 5+ 3
3×5+3+ 15+3 15
=
5−3
18+4 15
=
2
=9+2 15
=9+ 60
AnswerMarks Guidance
Obtains 18+4 151.1b B1
Obtains denominator of 21.1b B1
Obtains 9+ 60
AnswerMarks Guidance
Accept a = 9, b = 601.1b B1
Question 3 Total4
QMarking instructions AO
Question 3:
3 | Multiplies numerator and
denominator by conjugate of the
denominator
Condone missing brackets | 1.1b | B1 | 3+3 5 5+ 3
×
5− 3 5+ 3
3×5+3+ 15+3 15
=
5−3
18+4 15
=
2
=9+2 15
=9+ 60
Obtains 18+4 15 | 1.1b | B1
Obtains denominator of 2 | 1.1b | B1
Obtains 9+ 60
Accept a = 9, b = 60 | 1.1b | B1
Question 3 Total | 4
Q | Marking instructions | AO | Marks | Typical solution
Express $\frac{\sqrt{3} + 3\sqrt{5}}{\sqrt{5} - \sqrt{3}}$ in the form $a + b\sqrt{c}$, where $a$ and $b$ are integers.

Fully justify your answer.
[4 marks]

\hfill \mbox{\textit{AQA AS Paper 1 2024 Q3 [4]}}