Part 19 - Rationalisation II | Maths Made Easy

Surds GCSE Maths Revision

Part 19 – Rationalisation II

Example:

Rationalise 2/(2+√3)

Worked Solution:

Use the formulae m/(n±√a)×(n∓√a)/(n∓√a)=(mn∓m√a)/(n^2-a²) and √ab≡√(a×b)≡ √a×√b

2/(2+√3)=2/(2+√3)×(2-√3)/(2-√3)=(2×2-2√3)/((2+√3)(2-√3))

=(4-2√3)/(4-2√3+2√3-√3×√3)

=(4-2√3)/(4-3)=(4-2√3)/1

=4-2√3


Your turn:

Rationalise \frac{3}{3+\sqrt{4}}

Your answer can be written in the form \frac{a - 3\sqrt{4}}{b}

Find the value of a and b.

 

Enter your answer here:
a =
b =

Need some extra help? Find a tutor now

Or, call 020 3633 5145