© examsiri.com
Question : 33 of 160
Marks:
+1,
-0
Solution:
For two vectors
a and
b, it is given
a+b is also unit vector, so
|a+b|=1⇒(a+b)2=1 ⇒|a|2+|b|2+2a⋅b=1⇒1+1+2a⋅b=1
⇒‌‌a⋅b=−‌ Let angle between
a and
b is
‌′θ Then
cos‌θ=−‌⇒θ=120∘
© examsiri.com
Go to Question: