What is the angle between `hati+hatj and hati` ?

Options

A. `15^(@)`
B. `30^(@)`
C. `45^(@)`
D. `60^(@)`

Answer

C

Explanation

The angle between two vectors `vec A and vec B` is calculated by using,
`cos theta =(vec A cdot vec B)/(AB) hati, hatj and hatk` are unit vectors
`therefore cos theta =((hati+hatj)cdot hati)/(sqrt(1^(2)+1^(2))sqrt(1^(2)))`
`therefore cos theta =(1)/(sqrt(2)xxsqrt(1)) =(1)/(sqrt(2))`
`therefore theta =45^(@)`