Countdown to Exams - Day 81 - Surds and rationalising the denominator
Today we focus our attention on the topic of Surds and rationalising the denominator. You need to understand that Surds are expressions that contain an irrational square root (meaning, if you square rooted the number, you would get a never ending decimal). There are some laws of Surds that you need to be aware of (much like the laws of indices). Some questions will ask you to change a root to the form a√b, to do this you need to find the largest square number that will go into the number and simplify form there.
When it comes to rationalising the denominator, the key principle here is removing the square root from the denominator so that we are left with a whole number. This is achieved by multiplying. Take care to notice the different methods used when dealing with simple and more complex problems.
In the video below, Matt takes an in-depth look at surds and how to rationalise the denominator.
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