Download the app

Questions  

A vector  a=αi^+2j^+βk^, α,βR lies in the plane of the vectors b=i^+j^ and c=i^j^+4k^. If abisects the angle between b andc, . then

Remember concepts with our Masterclasses.

80k Users
60 mins Expert Faculty Ask Questions
a
a→.i^+1=0
b
a→.i^+3=0
c
a→.k^+4=0
d
a→.k^+2=0

Ready to Test Your Skills?

Check Your Performance Today with our Free Mock Tests used by Toppers!

detailed solution

Correct option is D

Angle bisector can be  a→=λb^+c^  or   a→=μb^−c^Now a→=λi^+j^2+i^-j^+4k^32=λ323i^+3j^+i^−j^+4k^=λ324i^+2j^+4k^          Comparing  with a→=αi^+2j^+βk^ we get                                               2λ32=2⇒λ=32          ⇒a→=4i^+2j^+4k^                   None of the option is satisfied. So, now considera→=μi^+j^2−i^−j^+4k^32      ⇒a→=μ323i^+3j^−i^+j^−4k^               =μ322i^+4j^−4k^                               Comparing witha→=αi^+2j^+βk^, we get    4μ32=2⇒μ=322⇒a→=i^+2j^−2k^Now a→.k^+2=-2+2=0


Similar Questions

 Vertices of a parallelogram taken in order are A(2,-1,4) , B(1,0,-1),C(1,2,3) and D. Distance of the point P(8,2,-12) from the plane of the parallelogram is - 


whats app icon
phone icon