The two lines represented by the equation $x^2 + xy + y^2 = 0$ are

If one of the lines given by $6x^2 - xy + 4cy^2 = 0$ is $3x + 4y = 0$,then $c$ equals

If one of the lines represented by the equation $ax^2 + 2hxy + by^2 = 0$ bisects the angle between the coordinate axes in the first quadrant,then which of the following is true?

If the sum of the slopes of the lines represented by $x^2 - 2xy \tan \theta - y^2 = 0$ is $4$,then $\theta =$

If $x^2+\alpha y^2+2 \beta y=a^2$ represents a pair of perpendicular lines,then $\beta$ equals to

The lines represented by the equation $3x^2 + 8xy - 3y^2 + 2x - 4y - 1 = 0$ and the line $4x - 3y - 2 = 0$: