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Question
If θ is the angle between two vectors `veca` and `vecb` then, `veca * vecb` ≥ 0, only when
Options
`0 < theta < pi/2`
`0 ≤ theta ≤ pi/2`
`0 < theta < pi`
`0 < theta < pi`
Solution
`0 ≤ theta ≤ pi/2`
Explanation:
`veca * vecb ≥ 0`
⇒ `|veca||vecb| cos theta ≥ 0`
Now, `|veca|` = + ve, = + ve ⇒ `cos theta ≥ 0`
Therefore, `0 ≤ theta ≤ pi/2`
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