The general equation of a linear function is ax + by + c = 0.
The exponents of both the x term and the y term are 1.
Another often used form of linear functions is y = mx + c.
The gradient of a straight line is a measure of its slope.
The gradient, m is defined as:
Sketching Straight Line Graphs
There are several ways to sketch the graphs of linear functions.
Find the two intercepts by putting x = 0 into the equation and finding the corresponding y value.
Then put y = 0 into the equation and find the corresponding x value.
This gives the values of x and y where the graph cuts the axes.
e.g. 3x + 2y = 6
Gradient / Intercept method.
If the equation is written in the form y = mx + c, where y is the subject of the equation, then:
m, the coefficient of x, is the gradient of the line,
and c, the constant term, is the y-intercept.
e.g. y = 2x + 1
Types of Lines