Yxcas's answer to .'s Secondary 4 A Maths Singapore question.

done {{ upvoteCount }} Upvotes
clear {{ downvoteCount * -1 }} Downvotes
Yxcas
Yxcas's answer
184 answers (A Helpful Person)
1st
Unit vector has a magnitude of 1 so just sub in the values to the formula and find α.