If the angle between unit vectors `veca and vecb is 60^(@)` . Then find the value of `|veca -vecb|`.

Explanation

`|veca-vecb|^(2)=(veca-vecb).(veca-vecb)`
`=a^(2)+b^(2)-2(veca.vecb)`
`1+1-2(1.1.costheta)`
`2(1-1/2)=1`