" The non-zero vectors a band a are related "a=8b" and "c=-7b" .Then the angle between "bar(a)" and "bar(c)" is "

The non-zero vectors a, b and c are related as b = 5a and c = -2b. The angle between a and c is

If bar(a) and bar(b) be non collinear vectors such that |bar(a)times bar(b)|=bar(a).bar(b) then the angle between bar(a) and bar(b) is

Let bar(a), bar(b), bar(c ) be unit vectors, suppose that bar(a). bar(b) = bar(a). bar(c )= 0 and the angle between bar(b) and bar(c ) is pi//6 then show that bar(a)= +-2 (bar(b) xx bar( c))

Let bar(a),bar(b),bar(c) be unit vectors such that bar(a)*bar(b)=bar(a).bar(c)=0 and the angle between bar(b) and bar(c) is (pi)/(6) if bar(a)=n(bar(b)xxbar(c)), then value of n is

bar(a),bar(b) and bar( c ) are unit vectors. bar(a).bar(b)=0=bar(a).bar( c ) and the angle between bar(b) and bar( c ) is (pi)/(3) . Then |bar(a)xx bar(b)-bar(a)xx bar( c )|= …………..

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

Let bar(a) and bar(b) be unit vector.If the vectors bar(c)=bar(a)+2bar(b) and bar(d)=5bar(a)-4bar(b) are perpendicular to the each other then angle between bar(a) and bar(b) is