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

If vec a and vec b are non - zero vectors and |vec a+ vec b| = |vec a - vec b| , then the angle between vec a and vec b is

If | vec a|+| vec b|=| vec c|a n d vec a+ vec b= vec c , then find the angle between vec aa n d vec bdot

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

If three unit vectors vec a , vec b ,a n d vec c satisfy vec a+ vec b+ vec c=0, then find the angle between vec aa n d vec bdot

Let vec a , vec b , vec c be three unit vectors and vec a . vec b= vec a . vec c=0. If the angel between vec b and vec c is pi/3 , then find the value of |[ vec a vec b vec c]| .

If vec a , vec b ,a n d vec c are such that [ vec a vec b vec c]=1, vec c=lambda vec axx vec b , angle, between vec aa n d vec b is (2pi)/3,| vec a|=sqrt(2),| vec b|=sqrt(3)a n d| vec c|=1/(sqrt(3)) , then the angel between vec aa n d vec b is a. pi/6 b. pi/4 c. pi/3 d. pi/2

If vec aa n d vec b are unit vectors such that ( vec a+ vec b).(2 vec a+3 vec b)xx(3 vec a-2 vec b)=0 , then angle between veca and vec b is a. 0 b. pi//2 c. pi d. indeterminate

If vec a and vec b are two non- zero vectors such that | vec a + vec b| = |vec a - vec b| , then show that vec a and vec b are perpendicular.

If vec axx vec b= vec cxx vec da n d vec axx vec c= vec bxx vec d , then show that vec a- vec d , is parallel to vec b- vec c provided vec a!= harr d and vec b!= vec c dot