A linear relationship (or linear association) is a statistical term used to describe the directly proportional relationship between a variable and a constant.

Functions The graph of f (x) = x 2 is the same as the graph of y = x 2. Writing graphs as functions in the form f (x) is useful when applying translations and reflections to graphs.

Learn how to use functions to represent translations, sketches, compressions and reflections of graphs with GCSE Bitesize Maths.