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Plotting Straight Line Graphs using Gradient Method Tutorial

math tutorials > plotting straight line graphs using gradient method

 

What is the gradient of a straight line graph?

The gradient of a line (symbol m) gives us information  about the steepness of a line and the direction in which it slopes.

 

Example

In  y = ½ x + 1,   the gradient is ½.

 

The gradient between 2 points


Gradient of a ilne

 

Gradient of a line

 

Note:

  1. Vertically, a step up is positive, a step down is negative.  Horizontally, a step to the right is positive, to the left is negative.
    Gradient of a lineGradient of a line
  2. A horizontal line has a gradient of 0.
  3. A vertical line is infinitely steep.  The gradient is undefined.

 

Drawing a graph form the equation y = mx + c.

  1. Identify the gradient (m).
  2. Identify and plot the y-intercept (c).
  3. Draw a line form the y-intercept with the correct gradient.

Graph problems for you to try

You may need to rearrange the equation into the form y = mx + c.

  1. y = x + 2
  2. y = -2x + 3
  3. y = ½x - 4
  4. x = y = 6
  5. 2x + 5y = 10