Pair of Straight Lines
Pair of Straight Lines: Overview
This topic covers concepts, such as Pair of Lines, Homogeneous Equation of Pair of Lines, Slopes of the Lines of a Homogeneous Pair, Angle between the Lines of a Homogeneous Pair, Parallel Lines in a Homogeneous Pair of Lines, etc.
Important Questions on Pair of Straight Lines

Find the angle between the lines joining the origin to the points of intersection of and .

If the lines are equally inclined to co-ordinate axes, then find the value of .

If the lines are equally inclined to co-ordinate axes, then find the value of .

If the equation represents a pair of lines, then

If the angle between the lines given by the equation is then

If the equation represents a pair of lines, then

The values of for which the equation represents a pair of straight lines are :

Consider a pair of perpendicular straight lines . The value of is:

If lines represented by are perpendicular to each other then = ….

Figure shows a square ABCD of side length unity whose diagonal's end points B and D are resting on x-axis and y-axis respectively as shown in figure. If vertices B and D starts to slide along x-axis and y-axis then vertices A and C moves on ax2 + 2hxy + by2 = 0. The value of a + h + b is:

The line meets the pair of straight lines in two points and . If is the origin and then the value of is


If the angle between the pair of straight lines represented by the equation is , where is a non-negative real number. Then is

Pair of straight lines perpendicular to each other represented by

If the angle between the two lines represented by is , then

The angle between the pair of straight lines , is

will represent a pair of straight lines, when

A value of for which the equation may represent a pair of straight lines is

If the equation represents a pair of straight lines, then
