# locus

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• Apr 16th 2013, 03:17 AM
Trefoil2727
locus
A straight line y=mx-5-2m meets x-axis and y-axis at point J and K respectively. Find the locus of the midpoint of JK when m is varied.
• Apr 16th 2013, 05:46 AM
zhandele
Re: locus
What have you tried? Do you have a formula for the midpoint in terms of m? If so, you should be able to treat m as a parameter and eliminate it. You'll get a function you can plot. See the pdf.
• Apr 16th 2013, 09:00 AM
HallsofIvy
Re: locus
Quote:

Originally Posted by Trefoil2727
A straight line y=mx-5-2m meets x-axis and y-axis at point J and K respectively. Find the locus of the midpoint of JK when m is varied.

You can determne K and J by setting x to 0 and solving for y and then setting y to 0 and solving for x. Then find the midpoint of those two points.
• Apr 18th 2013, 11:37 PM
Trefoil2727
Re: locus
but the answer given does not have m..
• Apr 18th 2013, 11:43 PM
MarkFL
Re: locus
Quote:

Originally Posted by Trefoil2727
but the answer given does not have m..

It was suggested that you eliminate the parameter m, can you state the parametric equations?