Step 7 Objective

Plot the graphs of linear functions, where y is given explicitly in terms of x; recognise that equations of the form y = mx + c correspond to straight-line graphs.


Probing questions

How do you go about finding a set of coordinates for a straight-line graph, for example y = 2x + 4?

How do you decide on the range of numbers to put on the x and y axes?

How do you decide on the scale you are going to use?

If you increase/decrease the value of m, what effect does this have on the graph? What about changes to c?

What have you noticed about the graphs of functions of the form y = mx + c? What are the similarities and differences?