#vector-trig thing

1 messages · Page 1 of 1 (latest)

twin ferry
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ok

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i am not sure about this but i think in this case we will not consider the quadrants of cos theta but instead consider the quadrants of a unit circle. Coz i think the question was "in what quadrant theta lies in" not cos theta

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i might be wrong

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no the question does not state that

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all it states is find theta

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then quadrants have nothing to do in here
lol

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ok then if they dont then why can i not just right -pi/3

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does the cos not matter

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plus the answer says 2pi/3

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it is because we can only cancel cos^-1(cos theta)= theta not cos^-1(cos -theta)

twin ferry
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so then why have they written 2pi/3

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and not -pi/3

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-pi/3 is not possible because you can't cancel cos^-1 of anything negative

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ye k makes sense

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ty