Edexcel IGCSE Maths 复习笔记 3.6.2 Straight Lines - Drawing Graphs

Edexcel IGCSE Maths 复习笔记 3.6.2 Straight Lines - Drawing Graphs

How do we draw the graph of a straight line from an equation?

  • Before you start trying to draw a straight line, make sure you understand how to find the equation of a straight line – that will help you understand this
  • How we draw a straight line depends on what form the equation is given in
  • There are two main forms you might see:y = mx + c and ax + by = c
  • Different ways of drawing the graph of a straight line:
  1. From the form y = mx + c 

    (you might be able to rearrange to this form easily)plot c on the y-axis

    go 1 across, m up (and repeat until you can draw the line)

  2. From ax + by = c 

    put x = 0 to find y-axis interceptput y = 0 to find x-axis intercept

    (You may prefer to rearrange to y = mx + c and use above method)

Exam Tip

It might be easier just to plot ANY two points on the line (a third one as a check is not a bad idea either) or use the TABLE function on your calculator.

Worked Example