Graphing Direct VariationDate: 02/27/2003 at 15:06:24 From: Jennifer Subject: How do you graph direct variation How do you graph direct variation? I thought you had to have two coordinates to graph a line. How do you do it with the formula y = mx+b? Example: y = 2x-3 Thanks for your help. Jennifer Date: 02/27/2003 at 17:59:53 From: Doctor Douglas Subject: Re: How do you graph direct variation Hi, Jennifer! Direct variation between x and y means that the relationship between them is of the form y = k*x where k is some constant. This means that the origin (0,0) is a point on this line, and so it only takes one additional point (x0,y0) to specify the line: y = k*x = (y0/x0)*x So it IS of the form y = mx+b, except that b must be zero in the case of direct variation. Does that help? Write back if you still have questions about this. - Doctor Douglas, The Math Forum http://mathforum.org/dr.math/ |
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