Given θ is the angle between the lines x2+2hxy+by2=0 To find Angle between x2+2xy‌sec‌θ+y2=0 Since, we know that angle between the line ax2+2hxy+by2=0 is tan‌θ=|
2√h2−ab
a+b
| Here, a=1 tan‌θ=|
2√h2−b
1+b
| ...(i) For x2+2xy‌sec‌θ+y2=0 a=1,h=sec‌θ,b=1 Let θ be the angle, then tan‌ϕ=|