Question

A Two vectors A and B are such that(A) = 4, (B)= 6, and (A-B)= 5. Find (A + B).
​

Answer 1

we have to use the identity (a+b ) ^2 = a^2+b^2 + 2ab then the answer is 4×4+6×6+2×4×6 = 52+48=100

Explanation:

use the identity a+b ) ^2