How do you graph #y=x-7# by plotting points?

1 Answer
KillerBunny
Jun 20, 2018

Sample two points from the equation and connect them

Explanation:

First of all, notice that you want to plot a line. In fact, your function is like #y=p(x)#, with #p(x)# being a first degree polynomial, and every first degree polynomial represents a line.

Now, to draw a line you only need two points. If you extend the segment connecting those two points, you have your line.

And finally, to sample points from an equation, you simply choose two arbitrary values for the independent variable #x#, and compute the values of the dependent variable #y#.

So, if we choose, for example, #x=0#, we get

#y = 0 - 7 = -7#

So, the line passes through the point #P_1 = (0,-7)#

Similarly, choose #x=10# to get

#y = 10-7=3#

So, the line passes through the point #P_2 = (10,3)#

Draw #P_1# and #P_2#, connect them and you have your line.

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