If unit vectors ` vec aa n d vec b` are inclined at angle `2theta` such that `| vec a- vec b|<1a n d0lt=thetalt=pi,t h e ntheta` lies in interval a.`[0,pi//6]` b. `[5pi//6,pi]` c. `[pi//6,pi//2]` d. `[pi//2,5pi//6]`

If \ vec a\ a n d\ vec b are two unit vectors inclined at an angle theta such that |a+b|,1, then theta (2pi)/3 c. pi/3

A solution of the equation cos^2theta+sintheta+1=0 lies in the interval a. (-pi//4,pi//4) b. (pi//4,3pi//4) c. (3pi//4,5pi//4) d. (5pi//4,7pi//4)

If | vec a+ vec b|<| vec a- vec b|, then the angle between vec aa n d vec b can lie in the interval a. (pi//2,pi//2) b. (0,pi) c. (pi//2,3pi//2) d. (0,2pi)

If t a nalpha=5/2 , tanbeta=-7/9 where alpha in [pi/2,pi] , then alpha+beta lies in the interval. [(3pi)/2,(7pi)/3] (b) [(13pi)/6,(5pi)/2] [(13pi)/6,(7pi)/3] (d) [pi/6,pi/3]

If theta is the angle between two vectors vec a\ a n d\ vec b ,\ t h e n\ vec adot vec bgeq0 only when 0

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)) , then the angle between vec a and vec b is a. 3pi//4 b. pi//4 c. pi//2 d. pi

If the vectors vec aa n d vec b are linearly idependent satisfying (sqrt(3)tantheta+1 )veca+(sqrt(3)s e ctheta-2) vec b=0, then the most general values of theta are a. npi-pi/6, n in Z b. 2npi+-(11pi)/6, n in Z c. npi+-pi/6, n in Z d. 2npi+(11pi)/6, n in Z

If vec a,vec b,vec c are three vectors such that vec a=vec b+vec c and the angle between vec b and vec c is pi/2, then

If vec a\ a n d\ vec b be two unit vectors and theta is the angle between them. Then vec a+ vec b\ is an unit vector, if theta= pi/2 b. (2pi)/3 c. pi/4 d. pi/3

If vec a and vec b are two vectors, such that vec a.vec b <0 and | vec a.vec b|=| vec axx vec b|, then the angle between vectors vec a and vec b is a. pi b. 7pi//4 c. pi//4 d. 3pi//4