Understanding Trig Quadrants and the Role of |k| ≥ 1 in Solving for θ

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To determine the quadrant of angle θ, it's essential to recognize that an obtuse angle is defined as being between 90 and 180 degrees, placing it specifically in the second quadrant. The discussion clarifies that while θ cannot be in the first quadrant, it cannot be in the third or fourth quadrants either. The notation |k| ≥ 1 is used to ensure that θ remains a real angle. Additionally, angles between 180 and 360 degrees are referred to as reflex angles. Understanding these definitions is crucial for solving trigonometric problems accurately.
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I'm just curious on how to find out what quadrant θ is in from the information. I know it says that theta is obtuse, but doesn't this only conclude that theta is not in the first quadrant? In the solutions they have right away said theta is obtuse therefore it is in the second quadrant so k is < 0, which I can understand but couldn't theta be in the 3rd & 4th quadrant also? Also what is |k|≥ 1 used for?

EDIT: nevermind, I though obtuse was just >90, not between 90 and 180 :x - If anyone could answer what |k| is for it'd help thanks.
 
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The name for angles that are between 180 and 360 are called reflex.

And as for the |k|\geq 1 this is probably just enforcing that \theta is real.
 
Mentallic said:
The name for angles that are between 180 and 360 are called reflex.

And as for the |k|\geq 1 this is probably just enforcing that \theta is real.

thanks again.
 

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