Solution: Angle between lines with slope m1 & m2 is given by tan θ = |( m2-m1)/( 1 + m1m2)| Here θ = π / 4, m1 = ½, we need to find m2
Putting these values in the equation, we get tan π / 4 = |( m2-1 / 2)/( 1 + ½ * m2)| or 1 = |( m2-1 / 2)/( 1 + ½ * m2)| Solving this we get m2 = 3 or-1 / 3 Collinearity of 3 points
If two lines having same slope pass through a common point, then two lines will coincide.
Hence, if A, B and C are Collinear if and only if slope of AB = slope of BC.
Various forms of Equation of line o o o
Horizontal and vertical lines Point-slope form Two-point form