If the `P. V.'s` of `A, B,C` are `3bari + 4barj+6bark, 4bari-6barj+3bark` and `-6bari+ 3barj+4bark` then the incentre of `DeltaABC` is

[bari-barj bark]+[-bari-barj bark]+[bari-bark bark] =

If the position vectors of A,B and C are respectively 2bari-barj+bark, bari -3barj-5bark and 3bari - 4barj - 4bark, " then " cos^(2) A =

If the volume of tetrahedron with edges bari+barj-bark,bari+abarj+bark and bari+2barj-bark is a/6 then a=

If the position vectors of the points A, B and C are -2bari+barj-bark , -4bari+2barj+2bark and 6bari-3barj-12bark respectively and barAB=lambdabarAC , then find the value of lambda .

If the three vectors 2bari -barj +bark, bari+ 2barj -3bark, 3bari + lamdabarj + 5bark are coplanar then lamda =

If bara = 3bari - 4barj +5bark, barb = 2bari+3barj-bark ," then the angle between " bara and barb is

If bara=2bari+barj-3bark, barb=3barj-2barj-bark then find the angle between .

If bar(AB)=3bari - 4barj-bark, bar(BC) =4bari -barj+3bark are two sides of a DeltaABC, " then " angleC =

Prove that the vectors bara= 2bari - barj + bark, barb = bari -3barj -5bark and barc=3bari -4barj -4bark are coplanar.