Question

Obtain the magnitude and direction cosines of vector (A-B), if A=2hati+3hatj+hatk, B=2hati+2hatj+3hatk

Answer 1

0,15–√,−25–√

0,25–√,15–√

0,0,15–√

none of these

Solution :

(a) (A−B)=2iˆ+3jˆ+kˆ−2iˆ−2jˆ−3kˆ=jˆ−2kˆ

|A−B|=1+4−−−−√=5–√

Direction cosines =05–√,15–√,−25–√