2. Questions Bank
  3. JEE Main & Advanced
  4. Mathematics
  5. Straight Line

JEE Main & Advanced Mathematics Straight Line Question Bank Slope of line, Equation of line in different forms

  • question_answer
    A straight line moves so that the sum of the reciprocals of its intercepts on two perpendicular lines is constant, then the line passes through                        [IIT 1977]

    A)            A fixed point                            

    B)            A variable point

    C)            Origin                                       

    D)            None of these

    Correct Answer: A

    Solution :

               Take two perpendicular lines as the coordinate axes. If a, b be the intercepts made by the moving line on the coordinate axes, then the equation of the line is                                 \[\frac{x}{a}+\frac{y}{b}=1\]                                            .....(i)                    According to the question \[\frac{1}{a}+\frac{1}{b}=\frac{1}{k}\], (say)                    i.e.,    \[\frac{k}{a}+\frac{k}{b}=1\]                                                               .....(ii)                    The result (ii) shows that the straight line (i) passes through a fixed point (k, k).


You need to login to perform this action.
You will be redirected in 3 sec spinner