Home
Class 12
MATHS
If veca, vecb are unit vertors such th...

If ` veca, vecb ` are unit vertors such that `veca -vecb` is also a unit vector, then the angle between ` veca and vecb` , is

A

`pi/6`

B

`pi/3`

C

`pi/4`

D

`pi/2`

Text Solution

Verified by Experts

The correct Answer is:
B
Let `theta` the angle between unit vectors ` veca and vecb` .
Then ,
` |veca -vecb|=1 `
` Rightarrow |veca -vecb|^(2) =1 `
` Rightarrow |veca|^(2) +|vecb|^(2) -2 (veca .vecb)=1`
` Rightarrow 1+1 -2|veca||vecb| cos theta =1`
` Rightarrow 2-2 cos theta =1 Rightarrow cos theta = 1/2 Rightarrow theta = pi/3`
Promotional Banner

Topper's Solved these Questions

  • SCALER AND VECTOR PRODUCTS OF TWO VECTORS

    OBJECTIVE RD SHARMA|Exercise Section I - Solved Mcqs|12 Videos

  • SCALAR AND VECTOR PRODUCTS OF THREE VECTORS

    OBJECTIVE RD SHARMA|Exercise Exercise|65 Videos

  • SOLUTIONS OF TRIANGLES

    OBJECTIVE RD SHARMA|Exercise Exercise|20 Videos

Similar Questions

Explore conceptually related problems

If veca,vecb are two unit vectors such that |veca + vecb| = 2sqrt3 and |veca -vecb|=6 then the angle between veca and vecb , is

If veca and vecb are two vectors such that |veca xx vecb|= veca.vecb , then what is the angle between veca and vecb ?

If veca, vecb, vecc are unit vectors such that veca. Vecb =0 = veca.vecc and the angle between vecb and vecc is pi/3 , then find the value of |veca xx vecb -veca xx vecc|

If |veca - vecb|=|veca| =|vecb|=1 , then the angle between veca and vecb , is

If veca, vecb,vecc are unit vectors such that veca.vecb = 0= veca.vecc and the angle between vecb and vecc is pi//3 then the value of |vecaxxvecb -veca xx vecc| is

If |veca.vecb|= |veca xx vecb| , then the angle between veca and vecb is

Let veca and vecb be two vectors such that |2 veca + 3 vecb| = |3 veca + vecb| and the angle between veca and vecb is 60^(@) . If 1/8 veca is a unit vector, then |vecb| is equal to :

If veca and vecb are unit vectors such that (veca +vecb). (2veca + 3vecb)xx(3veca - 2vecb)=vec0 then angle between veca and vecb is

If veca and vecb are two unit vectors such that veca+2vecb and 5veca-4vecb are perpendicular to each other, then the angle between veca and vecb is