Ever wonder what sorts of errors freshman math students make? There are a couple of pretty basic ones.

Solving word problems resulting in linear or quadratic equations and inequalities Definition of a function, domain, range, zeros, notation, composition, piecewise functions, inverse functions and ...

Linear equations can be shown on a graph. Find out how to create one in this Bitesize KS3 maths video.

I displayed these d values on the graph for you. Notice that they are the vertical distance from the real data points to the fitting linear function. Why this way?