MYTUTOR SUBJECT ANSWERS

246 views

Rationalising the denominator (Surds)

When asked to rationalise simple Surd (square roots that cannot be reduced to a whole number) fractions in the form a/√b we are aiming to remove the surd in the denominator (bottom).

----------------------------------------

e.g 1. Rationalise 3/√2 

Answer: We multiply the entire fraction by the denominator √2/√2 (this is equivalent to 1).

Let us first consider what happens to the denominator:

√2 x √2 = 2 (any simple surd multiplied by itself equals the number inside)

The numerator (top) becomes 3 x √2 or 3√2 

So the fraction rationalises to 3√2 / 2,  the surd has now been removed from the denominator.

Typically you will be asked to simplify the fraction which is just asking you to rationalise it. The rationalised fraction can be used more easily in further calculations.

Galen Y. GCSE Chemistry tutor, GCSE Maths tutor, GCSE Biology tutor, ...

10 months ago

Answered by Galen, a GCSE Maths tutor with MyTutor

Still stuck? Get one-to-one help from a personally interviewed subject specialist

327 SUBJECT SPECIALISTS

£20 /hr

Bryan P.

Degree: Mathematics (Bachelors) - Bristol University

Subjects offered: Maths, Further Mathematics

Maths
Further Mathematics

“I am currently a BSc Mathematics student at the University of Bristol and I am already no stranger to teaching.I have worked as a teaching assistant in my secondary school's maths department where I also led one-on-one sessions with ...”

£18 /hr

Charlotte G.

Degree: Medicine (Bachelors) - University College London University

Subjects offered: Maths, Chemistry+ 2 more

Maths
Chemistry
Biology
.BMAT (BioMedical Admissions)

“About Me: I am a medical student at University College London (UCL) who has always had a real passion for science and finding out how things work. I adore Medicine, I very much enjoyed learning about biology, maths and chemistry at s...”

MyTutor guarantee

£22 /hr

Hinsum W.

Degree: Medicine (Bachelors) - Edinburgh University

Subjects offered: Maths, Chemistry+ 3 more

Maths
Chemistry
Biology
-Personal Statements-
-Medical School Preparation-

“Hi, I'm a first year medic at Edinburgh. I've had 7 years' worth of experience teaching children Maths and English and have mentored lower school peers, so I'm bound to have an approach that will suit your learning style!”

About the author

Galen Y.

Currently unavailable: for regular students

Degree: materials science and engineering (Masters) - Imperial College London University

Subjects offered: Maths, Electronics+ 2 more

Maths
Electronics
Chemistry
Biology

“About Me:  Hi I'm Galen. Currently I’m a student at Imperial College London studying materials science and engineering. I’ve been lucky enough to work with lots of people from different backgrounds so I’m sociable and patient. Natural...”

MyTutor guarantee

You may also like...

Other GCSE Maths questions

Lisa, Max and Punita share £240 in the ratio 3 : 4 : 8 How much more money than Lisa does Punita get?

Solve: 3(x - 2) = 21

Work out the value of 125 to the power of -2/3.

How do you go about rearranging equations where the required subject appears on both sides? Such as making x the subject of 7x + a = 3x + b.

View GCSE Maths tutors

Cookies:

We use cookies to improve our service. By continuing to use this website, we'll assume that you're OK with this. Dismiss

mtw:mercury1:status:ok