If r⃗ =(i^+2j^+3k^)+λ(i^+j^+k^) and r⃗ =(i^+2j^+3k^)+μ(i^+j^−k^) are two lines, then the equation of acute angle bisector of two lines is

[a] Lines are r⃗ =(i^++2j^+3k^)+λ(i^−j^+k^) And r⃗ =(i^+2j^+3k^)+μ(i^+j^−k^) Along vectors (i^−j^+k^) and (i^+j^−k^) Respectively. Angle between two lines =cos−1((1)×(1)+(−1)(1)+(1)(−1)3√3√) =cos−1(−13√) Which is an obtuse angle. ∴ Vector along acute angle bisector =λ[i^−j^+k^3√−i^+j^−k^3√]=2λ3√(−j^+k^) ∴ Equation of acute angle bisector =(i^+2j^+3k^)+t(j^−k^)