If (a₁, b₁, c₁) and (a₂, b₂, c₂) be the direction ratios of two parallel lines then

The angle between two lines having direction ratios 1, 1, 2 and 4 is

The straight line is

If a line makes angles α, β and γ with the x-axis, y-axis and z-axis respectively then (sin² α + sin² β + sin² γ) = ?

If the points A(-1, 3, 2), B(-4, 2, -2) and C(5, 5, λ) are collinear then the value of λ is