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<theta<pi/2` b. `0lt=thetapi/2` c. `0<theta<

Question

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 `0A. `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 1

Correct Answer - B
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)`