[" Let "2" and "hat b" be two unit vectors.If "],[" Pectors "c=hat a+2hat b" and "vec d=5hat a-4hat b],[" perpendicular to each other,then the "],[" angle between "hat a" and "hat b" is : "]

Let hat a and hat b be two unit vectors. If the vectors vec c= hat a+2 hat b""a n d"" vec d=5 hat a-4 hat b are perpendicular to each other, then the angle between hat a and hat b is (1) pi/6 (2) pi/2 (3) pi/3 (4) pi/4

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

Find lambda if the vectors vec a=hat i-lambda hat j+3 hat k and vec b=4 hat i-5 hat j+2 hat k are perpendicular to each other.

If hat a and hat b are unit vectors such that [ hata hatb hatatimeshatb ]= (1)/(4) ,then the angle between hat a and hat b ,is equal to

For what value of lambda are the vector vec a=2 hat i+lambda hat j+ hat k\ a n d\ vec b= hat i-2 hat j+3 hat k perpendicular to each other?

If hat(a) and hat(b) are unit vectors such that (hat(a) + hat(b)) is a unit vector, what is the angle between hat(a) and hat(b) ?

If hat(a) and hat(b) are unit vectors such that (hat(a) + hat(b)) is a unit vector, what is the angle between hat(a) and hat(b) ?

For what value lambda are the vectors vec a=2 hat i+\ lambda hat j+ hat k\ a n d\ vec b= hat i-\ 2 hat j+3 hat k perpendicular to each other?