# maths

• Created by: franab
• Created on: 30-03-15 17:08

## Algebraic Fractions

• Algebraic fractions can be cancelled down. The numerators and denominators must be fully factorised first.
• If numerator and denominaros contain fractions then you can multiply both by the lowest common multiple to create an equivalent fraction
• to multiply fractions, multiply the numerators and multiply the denominators
• To divide two fractions, multiply the first fraction by the reciprocal of the second.
• To add (or subtract) fractions, each one must have the same denominator. Find lowest common multiple to do this.
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## Functions

• A one-to-one function is wwhere every element of the domain is mapped tto one element in the range.
• Many mappings can be made into functions by changing the domain. E.g. the mapping 'positive square root' can be changed into the function f(x)=by having a domain of x>0
• A composite function is two or more functions combined:
• g(x)=2x + 3, f(x)= x2
• fg(4)=f(2 x 4 + 3) = f(11) = 121
• The inverse funtion performs the opposite operation to the function. To calculate the inverse, change the subject of the formula.
• The range of the function is the domain of the inverse. The domain of the function is the range of the inverse.
• The inverse graph is a reflection of the function in the line y = x
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