Given that `(vec x-hat a).(vec x+hat a)=8` and `vec x.hat a=2` ,then the angle between `(vec x-hat a)` and `(vec x+hat a)` is
(A) `cos^(-1)((3)/(sqrt(14)))`
(B) `cos^(-1)((3)/(sqrt(21)))`
(C) `cos^(-1)((5)/(sqrt(21)))`
(D) `cos^(-1)((4)/(sqrt(21)))`

In a quadrilateral A B C D , vec A C is the bisector of vec A Ba n d vec A D , angle between vec A Ba n d vec A D is 2pi//3 , 15| vec A C|=3| vec A B|=5| vec A D|dot Then the angle between vec B Aa n d vec C D is cos^(-1)(sqrt(14))/(7sqrt(2)) b. cos^(-1)(sqrt(21))/(7sqrt(3)) c. cos^(-1)2/(sqrt(7)) d. cos^(-1)(2sqrt(7))/(14)

If vec A =4 hat I + 6 hat j -3 hat k and vec B =- 2 hat I -5 hat j + 7 hat k , find the angle between vec A and vec B .

If vec(a) = 5 hat(i) - hat(j) - 3 hat(k) and vec(b) = hat(i) + 3 hat(j) - 5 hat(k) , find the angle between vec(a) and vec(b) .

If vec(a)=(hat(i)+2hat(j)-3hat(k)) and vec(b)=(3hat(i)-hat(j)+2hat(k)) then the angle between (vec(a)+vec(b)) and (vec(a)-vec(b)) is

If vec A=hat i+hat j+hat k,vec B=4hat i+4hat j+4hat k and vec R=vec A+vec B then angle that vec R makes with vec A is

If |vec(a)| = sqrt(2) , |vec(b)| = 7 and vec(a) xx vec(b) = 2 hat(i) + 6 hat(j) + 3 hat(k) . Find the angle between vec(a) and vec(b) .

If vec a=hat i+hat j+hat k and vec b=hat j-hat k, find a vector vec c such that vec a x vec c=vec b and vec a*vec c=3

If a unit vector hat a in the plane of vec b=2 hato+ hat j& vec c= hat i- hat j+ hat k is such that vec a vec d where vec d= hat j+2 hat l , then hat a is ( hat i+ hat j+ hat k)/(sqrt(3)) (b) ( hat i- hat j+ hat k)/(sqrt(3)) (2 hat i+ hat j)/(sqrt(5)) (d) (2 hat i- hat j)/(sqrt(5))

Find the angle between (vec(a)+vec(b)) and (vec(a)-vec(b)) , if vec(a)=(2 hat(i)-hat(j)+3hat(k)) and vec(b)=(3hat(i)+hat(j)+2hat(k)) .

vec a=3hat i-hat j-4hat k,vec b=-2hat i+4hat j-3hat k and vec c=hat i+2hat j-hat k,f in d|3vec a-2vec b+4vec c|