How do you graph #y=1/4x-1# using slope intercept form?

1 Answer
Nov 12, 2017

A line passing through #(0,-1)# and #(4,0)#

graph{1/4x-1 [-7.82, 12.18, -4.6, 5.4]}

Explanation:

We need to find two points, then join up the line. The natural points to go for are those on the x-axis and the y-axis.

To find the point where it crosse the y-axis:

Let #x=0#
#y=1/4(0)-1#
#y=-1#
#:.# crosses at #(0,-1)#

You can also tell this from the value of #c# from the general equation #y=mx+c#, as, if #x=0, y=c# Since #c=-1#, it passes through #(0,-1)#, although I'd say its more formal to go through the algebra.

Now to find where it crosses the x-axis:

Let #y=0#
#0=1/4x-1#
#1=1/4x#
#x=4#
#:.# crosses at #(4,0)#

We can now join up these two points like so:

graph{1/4x-1 [-7.82, 12.18, -4.6, 5.4]}