Question 702498
{{{x=0}}} represents the y-axis, the collection of points with {{{x=0}}}.
We call it a vertical line.
Any {{{x=constant}}} equation graphs as a vertical line.
Any {{{y=constant}}} equation graph as a "horizontal" line.
What I would call a slanted line has an equation with x and y.
If the equation looks like y = (something)x + constant,
then that something is the slope.
To graph a slanted line, you need two points.
You would want to calculate (and maybe tabulate) your points before you start graphing,
so as to know what part of your x-axis and y-axis the graph must show.
My table for {{{y=3x-2}}}would look like this:
{{{drawing(150,100,-2,4,-2,2,
line(-2,0,4,0),line(0,-2,0,2),line(2,-2,2,2),
locate(-1.2,-0.6,y),locate(-1.2,1.2,x),
locate(0.8,-0.6,-2),locate(0.8,1.2,0),
locate(2.8,-0.6,4),locate(2.8,1.2,2)
)}}} with a row for the x's and a row for the y's,
but vertical tables, with columns for the x's and y's may be more popular.
Then, plotting the points, and connecting them with a straight line, would give you the graph:
{{{drawing(300,300,-5,5.5,-5,5.5,
grid(1),
blue(circle(0,-2,0.2)),blue(circle(2,4,0.2)),
blue(line(-2,-8,3,7))
)}}}
You want to choose points that are easy to calculate and give you a good graph.
Sometimes, if your two points are too close together, it is hard to draw the line accurately.
If it does not work in your first try, try again.
It could be easy to calculate two points.
Often, making {{{x=0}}} lets you easily calculate the corresponding value for {{{y}}}. That gives you the coordinates for one point.
Often, making {{{y=0}}} lets you easily calculate the corresponding value for {{{x}}}. That gives you the coordinates for one point.