# Surds

I really have nooo clue on what surds are.

Surds are square roots that cannot be reduced to a whole number e.g.
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05 July 2011
there are a few simple rules that we have to learn for surds
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05 July 2011
x=
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This means that if we have a question such as solve x
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05 July 2011
we put the 2 and the 8 inside the square root to get =
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now we know that = 4
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05 July 2011
so 4 is our final answer
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Rule 2 is very similar.....
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it just states that =
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e.g. = = =2
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05 July 2011
another type of question that you sometimes get asked is where you have to 'rationalise the denominator'
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05 July 2011
this means that if there is a surd in the denominator part of a fraction, you have to make it a 'rational' (whole) number
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e.g.
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to rationalise the denominator we have to multiply both the top and the bottom of the fraction by
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so we get
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now, due to another rule which states that our
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and we leave the surd on the top
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so now we have
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05 July 2011