4PM1/01 Jun 2019, Question 2: Surds
Pearson Edexcel International GCSE Further Pure Mathematics 4PM1 · Paper 1 · Calculator · 3 marks
اقرأ هذا الحل مشروحاً بالعربي ←
The question, in short
Rationalise the denominator of (4 + 2√3)/(5 − 2√3), express it as (a + b√3)/c with integers a, b and prime c, and state a, b and c.
Summarised in our own words. Use the official paper for the exact wording and any diagrams.
Solution · 3 marks
- 1Multiply top and bottom by 5 + 2√3
- 2Numerator: (4 + 2√3)(5 + 2√3) = 20 + 8√3 + 10√3 + 12 = 32 + 18√3
- 3Denominator: 25 − 4 × 3 = 13
- 4= (32 + 18√3)/13: a = 32, b = 18, c = 13
Answera = 32, b = 18, c = 13
Stuck on a step? Read the free lesson: Surds
Practise more surds questions
Real 4PM1 past-paper questions, marked on your working like the exam, with a worked solution for every part.
Practise free on LemmaraMore past-paper questions on surds
Also searched as: 4PM1 1 June 2019 · 4PM1/01 · 4pm1 jun19 1 · question 2.
Lemmara is an independent study tool, not affiliated with or endorsed by Pearson Edexcel. The worked solutions are Lemmara’s own.