Functions

• You need to be able to work with function notation confidently in your exam

Composite functions

• If you apply two functions one after the other, you can write a single function which has the same effect as the two combined functions

• This is called a composite function

Working it out

• Order is important in composite functions

• You can think of fg(x) as f(g(x))

• You work out g(x) first then you use this answer as your input for f(x)

• To find an algebraic expression for fg(x) you need to substitute the whole expression for g(x) for each instance of x in the expression for f(x)