two vectors equal have resultant equal to either find the angle between them

Asked by choudharypriya65490 | 8th Sep, 2020, 12:26: AM

Expert Answer:

Let begin mathsize 14px style straight theta end style be the angle between the two vectors A and B such that, |A| = |B|.

Therefore,

R= A+ B+ 2AB cosbegin mathsize 14px style straight theta end style

=> A= A+ A+ 2(A)(A) cosbegin mathsize 14px style straight theta end style    [since, |A| = |B| = |R|]

=> A= 2A+ 2Acosbegin mathsize 14px style straight theta end style

=> cosbegin mathsize 14px style straight theta end style = -1/2

=> begin mathsize 14px style straight theta end style = 120°

Answered by Shiwani Sawant | 8th Sep, 2020, 10:52: AM