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

2 Answers
Jul 30, 2015

The graph of your function is a straight line.

Explanation:

Your function #y=f(x)=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:

enter image source here

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->f(0)=0-4=-4#
#y=0 -> 0=x-4-> 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]}