If a and b are two vectors of magnitude 2 , each inclined at an 60^ , then angle between a and a + b is

Step-by-step solution

Let be angle between a and b then =60^ (given) aligned Since, | a + b |² &=| a |²+| b |²+2 a b &=4+4+ (2 2 2 60^ ) &=8+8 60^ =8+4=12 aligned | a + b |= 12 =2 3 Now, a ( a + b )=| a || a + b | x where x is angle between a and a + b . a a + a b =4 3 x 4+2 2 60^ =4 3 x 6=4 3 x x- 3 2 = 6 x=30^