Manipal MET2013MathematicsStraight Lines
A straight line cuts intercepts from the axis of coordinates the sum of the reciprocals of which is a constant K . Then it always passes through a fixed point
Options
- A(K, K)
- B( 1 K , 1 K )
- C(-K,-K)
- D(K-1, K-1)
Correct answer
B. ( 1 K , 1 K )
Step-by-step solution
Let the equation of the line be x a + y b =1 ....(i) Its intercepts on y and x axes are b and a respectively. According to the question, 1 a + 1 b = constant =K 1 a + 1 b = constant =K (say) 1 a K + 1 b K =1 1 / K a + 1 / K h =1 ....(ii) From (ii) it follows that line (i) passes tnorougn the fixed point ( 1 K , 1 K ) .