how do you tell if this is an obtuse angle? | Mathematics | Page 1

strange inletBOT Dec 22, 2023, 1:24 PM

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rustic thistle Dec 22, 2023, 1:25 PM

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I've gotten this so far

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but I'm not sure how to convert cos theta = -1/3 to degrees

limber phoenix Dec 22, 2023, 1:36 PM

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think about when cos(x) is negative (which quadrants, etc)

rustic thistle Dec 23, 2023, 4:40 AM

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Uhh

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Still kinda Confused

limber phoenix Dec 23, 2023, 7:31 PM

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Since this is a triangle, the angle will be between 0 and 180, i.e the first and second quadrant of the unit circle

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However, cos is negative only in the second quadrant, with an angle between 90 and 180

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This is by definition an obtuse angle

rustic thistle Dec 27, 2023, 9:23 AM

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.close

#how do you tell if this is an obtuse angle?