IIT JEE , AIEEE Forum - Mathematics , Analytical Geometry

Asmita

Let the eq. of the required line in the intercept form be x/a

y/b =

1.

Case 1 : when x/a + y/b =1 i.e. the line is going downwards from the left to the right of the cartesian plane.

Here a=b=k(say)

therefore x+y=k

but (2,2) lies on it Therefore 2+2=k=4

therefore the eq. of the line is x+y=4.

Case 2 :when x/a - y/b =

1 i.e. the line is going upwards from the left to the right of the cartesian plane.

Here a=b=p(say)

therefore l(x-y)l=p....(1)

but (2,2) lies on it Therefore 2-2=p=0

therefore from (1) the eq. of the line is x-y=0 i.e. x=y