Question

if
Ă = i+ 2j+ 2k and B = 2i + j - k
the magnitude of A&B​

Answer 1

Answer:

(1×2)i + (2×1)j +(2×(-1))k

=2i +2j -2k

now magnitude of A.B

(2²+2²+(-2)²)^½

=(4+4+4)^½

=(12)^½

=2(3)^½

now for mag of A and B seperatel

|A|=(1+2²+2²)^½

=(9)^½

=3

|B|=(2²+1²+(-1)²)^½

=(6)^½