For x ∈ (0, π), the equation sin x + 2sin2x −sin3x = 3 has
The angle θ between the vectors \(\rm \vec{a} = 5\hat{i} - \hat{j} + \hat{k}\) and \(\rm \vec{b} = \hat{i} + \hat{j} - \hat{k}\) equals to
If ABCD is a parallelogram, vector AB = 2i + 4j - 5k and vector AD = i + 2j + 3k, then the unit vector in the direction of BD is