# How do you graph f(x) = x -4?

Jul 30, 2015

The graph of your function is a straight line.

#### Explanation:

Your function $y = f \left(x\right) = x - 4$ is called Linear.
First you notice that the coefficient of $x$ is $1$; this number is the Slope of your line and, being $> 0$, tells you that your line is going up (as $x$ increases also $y$ increases).
To plot the graph we can choose two values of $x$ and evaluate the corresponding $y$, so:
if $x = 0$ then $y = 0 - 4 = - 4$
if $x = 2$ then $y = 2 - 4 = - 2$
we can now plot these two points and draw a line through them:

Jul 30, 2015

Find the coordinate of the points that intercept the axes. These are (0, -4) and (4, 0). Then trace a line passing through these points.

#### Explanation:

This is a linear function, its shape is a line and it only takes two points to trace. The two points chosen should be the intercepts of the axes. Therefore, you should solve:
$x = 0 \to f \left(0\right) = 0 - 4 = - 4$
$y = 0 \to 0 = x - 4 \to x = 4$
This gives you two dots:
When x=0, y=-4: (0, -4).
When y=0, x=4: (4, 0).
graph{x-4 [-10, 10, -5, 5]}