CIE A Level Maths: Pure 1复习笔记1.3.2 Composite Functions

What is a composite function?

• A composite function is where one function is applied after another function

• The ‘output’ of one function will be the ‘input’ of the next one
• Sometimes called function-of-a-function
• A composite function can be denoted
  •  

How do I work with composite functions?

• Recognise the notation

Special cases

• fg(x) and gf(x) are generally different but can sometimes be the same
• ff(x) is written as f²(x)
• Inverse functions ff^-1(x) = f^-1f(x) = x