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Analytical Geometry

P(1,3) is the image of Q(-3,1) in the line L. The equation to the line L is ?

Profile image of anand s
16 Years agoGrade
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1 Answer

Profile image of Rohith  Gandhi
16 Years ago

Dear Anand,

Since P is image of Q by reflection on line L. mid point of P and Q is on line L and the line is also perpendicular to the line joining points P and Q which is the general concept in finding line of reflection

mid point of p(1,3) and q(-3,1) is M[(1-3)/2,(3+1)/2]=>M(-1,2)

slope of line joining pq = (1-3)/(-3-1) = -2/-4 =1/2

let, slope of our line L is m

=> mX1/2 = -1 =>m = -2

therefore, equation of the line is,

y-y1 = m(x-x1)

in our case x1,y1 = (-1,2)

=> y-2 = -2(x+1)

=>y = -2x


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Rohith Gandhi P