If `|vec a+vec b|=|vec a-vec b|` prove that the angle between `vec a` and `vec b` is 90°

If vec a+ vec b+ vec c=0 and | vec a|=3,\ | vec b|=5 and | vec c|=7 , show that the angle between vec a and vec b is 60^0 .

Define vec axx vec b and prove that | vec axx vec b|=( vec a. vec btantheta, where theta is the angle between vec a and vec b ) .

If | vec a|=8,| vec b|=3 and | vec a x vec b|=12 , find the angle between vec a and vec bdot

The non-zero vectors are vec a,vec b and vec c are related by vec a= 8vec b and vec c = -7vec b . Then the angle between vec a and vec c is

Two vectors vec(a) and vec(b) are such that |vec(a)+vec(b)|=|vec(a)-vec(b)| . What is the angle between vec(a) and vec(b) ?

If vec a and vec b are two vectors such that | vec a|=4,| vec b|=3 and vec a . vec b=6 . Find the angle between vec a and vec b .

If |vec(a)+vec(b)|ge|vec(a)-vec(b)| then angle between vec(a) and vec(b) may be

If vec a and vec b are unequal unit vectors such that ( vec a- vec b)xx[( vec b+ vec a)xx(2 vec a+ vec b)]= vec a+ vec b , then angle theta between vec aa n d vec b is 0 b. pi//2 c. pi//4 d. pi

If vec a and vec b are unit Vectors, then what is the angle between vec a and vec b so that sqrt(2) vec a- vec b is a unit vector?

If vec a , vec b ,and vec c are non-coplanar unit vectors such that vec axx( vec bxx vec c)=( vec b+ vec c)/(sqrt(2)), vec b and vec c are non-parallel, then prove that the angel between vec a and vec b, is 3pi//4.