![\"\"](\"/images/stars/stars-13.gif\")
You can put this solution on YOUR website!
\n" ); document.write( "The other tutor didn't answer your question. Or, rather, he interpreted your question in a way I don't think you intended -- thinking that you were plotting a single point instead of a line.
\n" ); document.write( "If you are plotting a single point, \"y=3\" is not enough information; you need an x value also.
\n" ); document.write( "But plotting the line \"y=3\" is something very different.
\n" ); document.write( "In the equation \"y=3\", we are told nothing about x. That means x can be any number we choose; the only restriction is that y must be 3.
\n" ); document.write( "So if you plot a whole bunch of points using different x values, keeping the y value always 3, what does the graph look like?
\n" ); document.write( "It is a horizontal line, crossing the y-axis at (0,3).
\n" ); document.write( "Most beginning students think of the x value of a point as how far the point is horizontally from the origin, and the y value as how far the point is vertically from the origin.
\n" ); document.write( "But in fact the x value tells you how far you are from the y-axis, and the y value tells you how far you are from the x-axis.
\n" ); document.write( "So \"y=3\" tells you that you are 3 units from the x-axis; since it doesn't tell you anything about the x value, you can choose any x value you want. The resulting graph is a horizontal line.
\n" ); document.write( "Similarly, the equation \"x=4\" would tell you that you are 4 units to the right of the y-axis, without telling you anything about the y value. So the graph of x=4 is a vertical line crossing the x-axis at (4,0). \n" ); document.write( "