Algebraic fractions

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Contents:

A Simplifying algebraic fractions [2.9]

B Multiplying and dividing

algebraic fractions [2.9]

C Adding and subtracting

algebraic fractions [2.9]

D More complicated fractions [2.9]

Opening problem

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For the right angled triangle given, can you:

a write down expressions for cosμ, sinμ and tanμ in

terms ofx

b use these expressions to verify thatsinμ¥cosμ= tanμ?

Fractions which involve unknowns are calledalgebraic fractions.

Algebraic fractions occur in many areas of mathematics. We see them in problems involving trigonometry

and similar triangles.

CANCELLATION

We have observed previously that number fractions can be simplified by cancelling common factors.

For example,^1228 =^44 ££^37 =^37 where the common factor 4 was cancelled.

A SIMPLIFYING ALGEBRAIC FRACTIONS [2.9]

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x¡+2

q

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Y:\HAESE\IGCSE01\IG01_16\339IGCSE01_16.CDR Tuesday, 7 October 2008 2:01:41 PM PETER