If `theta` is the angle between two vectors ` vec a\ a n d\ vec b ,\ t h e n\ vec adot vec bgeq0` only when `0

Options

A. `0lt theta lt (pi)/(2)`
B. `0 le theta le (pi)/(2)`
C. `0 lt theta lt pi`
D. `0 le theta le pi`

Answer

B

Explanation

It is given that, `vec(a) . vec(b) ge 0`
We know that, `vec(a). vec(b) = |
vec(a)||vec(b)|cos theta ge 0`
`implies cos theta ge 0 implies 0letheta le (pi)/(2)`