Question

Find the equation of st. line passing through the point of intersection x+y+1=0 and 2x-y+5=0

Answer 1

Answer:

Any line through the intersection of given lines is P+λQ=0

or (x−3y+1)+λ(2x+5y−9)=0

Its slope will be infinite if it is perpendicular to x-axis i.e. parallel to y-axis.

Hence the coefficient of y will be zero.

∴−3+5y=0

or λ=3/5. Putting for λ the line is x−2=0. Clearly its distance from (0,0) is 2.