10th Class Mathematics Coordinate Geometry Question Bank Co-ordinate Geometry

  • question_answer
    The equation of line \[{{l}_{1}}\] is \[y=2x-4\]Line \[{{l}_{2}}\] parallel to line \[{{l}_{1}}\], and passes through point (0,6) is Which of the following is the equation of line \[{{l}_{2}}\]

    A)  \[y=2x+6\]                          

    B)  \[y=2x-6\]

    C)  \[y=2x+3\]        

    D)         \[y=2x+4\]

    Correct Answer: A

    Solution :

     Here, it is given that lines \[{{l}_{1}}\] and \[{{l}_{2}}\] are parallel. We know that, the parallel line on the co-ordinate planes have the same slope. i.e. line \[{{l}_{1}}\] must have the same slope as line \[{{l}_{2}}\] Equation of line \[{{l}_{1}}\] is \[y=2x-4.\] Compare if with \[y=mx+c\] from, Slope = co-efficient of x term = 2. So, line have slope = 2. Now, line \[{{l}_{1}}\] have the equation of form,                 \[y=2x+c.\] For finding the value of c which is a y-inter-cept of line; put \[x=0\]and \[y=6,\]as line crosses the y-axis at point \[(0,6)\]. \[\therefore \]  \[y=2x+c\] or          \[6=2(0)+c\] or             \[c=6\]. So, the equation of line \[{{l}_{1}}\] is \[y=2x+6.\]


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