L passes through (1,l) and makes an angle of tan−1‌
5
7
with x+y−3=0 tan‌θ‌‌=|‌
m+1
1−m
|=‌
5
7
7m+7‌‌=5−5m⇒m=−‌
1
6
7m+7‌‌=5m−5 m‌‌=−6 Equation of line when m‌‌=−6 y−1‌‌=−6(x−1) y‌‌=−6x+7 ⇒‌‌−6x−y+7‌‌=0 On comparing with ax+by+c=0 a‌‌=−6,c=7 ac‌‌=−42 m‌‌=−‌