Question
Question: In a triangle ABC, if A(2, –1) and 7x – 10y + 1 = 0 and 3x – 2y + 5 = 0 are equations of an altitud...
In a triangle ABC, if A(2, –1) and 7x – 10y + 1 = 0 and
3x – 2y + 5 = 0 are equations of an altitude and an angle bisector respectively drawn from B, then equation of BC is-
A
x + y + 1 = 0
B
4x + 9y + 30 = 0
C
5x + y + 17 = 0
D
x – 5y – 7 = 0
Answer
5x + y + 17 = 0
Explanation
Solution
BE ŗ 7x – 10y + 1 = 0
BN ŗ 3x – 2y + 5 = 0
So B ŗ (–3, –2), mAB = 51
DABN
tan q = 1+51.2351−23= 1 (Q q < p/2)
DABN 1 = 1+m−23m−23
Ž 5m2 + 24 m –5 = 0 Ž m = 51 or – 5
BC ŗ y + 2 = –5 (x + 3) Ž 5x + y + 17 = 0