Coupon Accepted Successfully!


Family of Straight Lines

Let L1a1x + b1y + c1 = 0 and L2a1x + b1y + c1 = 0. Then general equation of any straight line passing through the point of intersection of L1 and L2 is given by L1 + λL2 = 0, where λ R.
These lines form a family of straight lines. Also this general equation satisfies point of intersection of L1 and L2 for any value of λ.


  • Variable straight line ax + by + c = 0, where a, b, c are real form of a family of straight line as for different values of ab, c they are related by any linear relation, like al + bm + cn = 0, where lm, n are constants.
    For this given variable line can be adjusted as ax + by 73733.png = 0
    73727.png, which passes through point 73721.png for different value of a and b.
  • If a straight line is such that the algebraic sum of the perpendiculars drawn upon it from any number of fixed points is zero; then line always passes through a fixed point.

Test Your Skills Now!
Take a Quiz now
Reviewer Name