If θ is an angle between the lines given by the equation 6x2+5xy−4y2+7x+13y−3=0, then equation of the line passing through the point of intersection of these lines and making an angle θ with the positive x - axis is
11x−2y+13=0
Writing the given equation as a quadratic in x we have 6x2+(5y+7)x−(4y2−13y+3)=0
⇒ x=−(5y+7)±√(5y+7)2+24(4y2−13y+3)12=−(5y+7)±√121y2−242y+12112=−(5y+7)±11(y−1)12=6y−1812, −16y+412⇒ 2x−y+3=0 and 2x+4y−1=0
which are the two lines represented by the given equation and the point of intersection is (-1, 1), obtained by solving these equations.
Also tan θ=2√h2−aba+b where a = 6, b = -4, h=52
=2√(52)2−6(−4)6−4=√1214=112
So the equation of the required line is
y−1=112(x+1)⇒11x−2y+13=0