Let ` vec a` , `vec b` be two vectors of the same magnitude such that the angle between then is `60^0` and ` vec a* vec b=8.` Find `| vec a|` , `|vec b|`

Explanation

Given, ` vec a* vec b=8`


`|vec a|=|vec b|`


`cos theta=cos 60^o=(1)/(2)`



Scalar product: `vec a* vec b=|vec a| |vec b|costheta`


`8=|vec a|^2 (1)/(2)`


`|vec a|^2 =16`


`|vec a| =4`


`|vec a| =|vec b|=4`