Straight Line and Pair of Straight Lines 3 Question 9

10. The set of lines ax+by+c=0, where 3a+2b+4c=0 is concurrent at the point… .

(1982,2M)

True/False

Show Answer

Answer:

Correct Answer: 10. 34,12

Solution:

  1. The set of lines ax+by+c=0, where 3a+2b+4c=0 or 34a+12b+c=0 are concurrent at x=34,y=12 i.e. comparing the coefficients of x and y.

Thus, point of concurrency is 34,12.

Alternate Solution

As, ax+by+c=0, satisfy 3a+2b+4c=0 which represents system of concurrent lines whose point of concurrency could be obtained by comparison as,

ax+by+c3a4+24b+c

x=34,y=12 is point of concurrency.

34,12 is the required point.



NCERT Chapter Video Solution

Dual Pane