if `a+b=c` and `|a|=4 , |b|=6 , |c|=8` then angle between `a & b` is

If a is perpendicular to b and c, |a| = 2, |b| = 3, |c| = 4 and the angle between b and c is 2pi // 3 then [a b c] =

If a is perpedicular to b and c|a| = 2, |b| = 3 |c| = 4 and the angle between b and c is (2pi)/(3) , then [a,b,c] is equal to

If a+b+c=0 and |a|=sqrt(37),|b|=3, |c|=4 then the angle between b and c is

If a + b + c = 0 and |a| = 3, |b| = 4 and |c| = sqrt(37) the angle between a and b is

Ifa,b,c are vectors such that a + b + c = 0 and | a | = 7, | b | = 5,| c | = 3, then the angle between c and b is a) pi//3 b) pi//6 c) pi//4 d) pi

If three vectors a,b,c are such that a !=0 and a xx b = 2 (a xx c), |a| = |c| = 1, |b| = 4 and the angle between b and c is cos^(-1) (1/4), then b - 2c = lambda a where lambda =