SOLUTION: 26.) The midpoint of the line segment joining a moving point to (6,0) is on the line y=x. Find the equation of its locus. Ans. x-y+6=0 This is a question that comes with the

Algebra ->  Length-and-distance -> SOLUTION: 26.) The midpoint of the line segment joining a moving point to (6,0) is on the line y=x. Find the equation of its locus. Ans. x-y+6=0 This is a question that comes with the       Log On


   



Question 152310: 26.) The midpoint of the line segment joining a moving point to (6,0) is on the line y=x. Find the equation of its locus.
Ans. x-y+6=0

This is a question that comes with the answer but I don't know how to solve for it. I tried using the midpoint formula but the answer is either x+y-6=0 or x-y-6=0. I don't know how to solve for this kind of problem...

Answer by Edwin McCravy(20054) About Me  (Show Source):
You can put this solution on YOUR website!
26.) The midpoint of the line segment joining a moving point to (6,0) is on the line y=x. Find the equation of its locus.
Ans. x-y+6=0


Graph the line y=x:

graph%28400%2C400%2C-7%2C13%2C-7%2C13%2Cx%29

Call point (6,0) the point R.

Draw an arbitrary line from point R(6,0), crossing the
line y=x at point M, and extending to P so that MP
equals RM. making M the midpoint of RP.  P is the moving
point.



Label the moving point P with the variable coordinates (x,y) 



Since point M is the midpoint of the line segment RP, we use
the midpoint formula to label M with the coordinates 
(%28x%2B6%29%2F2,%28y%2B0%29%2F2) or (%28x%2B6%29%2F2,y%2F2) 



Now the point M(%28x%2B6%29%2F2,y%2F2) is on the line y=x, so
it must satisfy the equation y=x, so we substitute that point 
into the equation y=x and we get:

y%2F2=%28x%2B6%29%2F2

Multiply both sides by 2:

y+=+x%2B6

That is equivalent to

x-y%2B6=0

To see the path of the moving point we draw the graph of
x-y%2B6=0 in green




Edwin