Each learning path is one chapter: a guided route through a topic, one small course at a time. Pick a class to see its chapters in order.
A taxi fare depends on the distance. The height of a ball depends on the time. A temperature in kelvin depends on a temperature in celsius. In each case, one number decides another, and mathematics has one word for this: a function. In this chapter we start from sets and relations, and we build the idea of a function with care. Then we draw functions, move and stretch their graphs, combine them, and undo them with the inverse. Python draws the graphs and checks our answers.