How do you graph #y=-2x# by plotting points?

1 Answer
Dec 23, 2016

See Explanation

Explanation:

#1.# The way to graph this with plotting points is that you choose random values for #x# and you can find out what your #y# value becomes.

#2.# For example let's pick #1#, #3#, and #5# for our #x# values.
If you plug in those #x# values into the function #y=-2x#, you get:

#y=-2(1)# so your #y# equals #-2#.
Therefore your point on the graph is #(1, -2)#.

#y=-2(3)# which equals #-6#.
So another point on the graph is #(3, -6)#.

#y=-2(5)# and that will give you #-10#.
So there you have another point on your graph which is #(5, -10)#.

You can carry on plugging in different values for #x# and see what your #y# becomes.

#3.# Finally you can plot and connect all the points on the graph and you will get a straight line. If that will pass through the point #(0, 0)#, and has a slope of #-2# which means whichever point you pick on the line you just drew, your graph goes down #2# and right #1#, down #2# right #1#, down #2# right #1#, and so on.

Here is the graph:

graph{-2x [-10, 10, -5, 5]}

Hope this helped (c: