Question

Find a unit vector parallel to the sum of the vectors r = 2i +4j - 5k and r2 = 2j + 3k​

Answer 1

First of all find the sum of the given two vectors a⃗ =2i+4j−5k,andb⃗ =i+2j+3k

That is a⃗ +b⃗ =3i+6j−2k

|a⃗ +b⃗ |=32+62+(−2)2−−−−−−−−−−−−−√=9+36+4−−−−−−−−−√=49−−√=7

Unit vector along a⃗ +b⃗ =a⃗ +b⃗ |a⃗ +b⃗ |=17(3i+6j−2k)