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Given that $ cos(θ) = -frac{1}{2} $, find the general solutions for $ θ $ in the unit circle.

Answer 1

Abigail Nelson

Emma Johnson

To solve for $ θ $ such that $ \cos(θ) = -\frac{1}{2} $, we need to find all angles in the unit circle where the cosine value is $ -\frac{1}{2} $. The cosine function is negative in the second and third quadrants.

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The reference angle for $ \cos(θ) = \frac{1}{2} $ is $ \frac{\pi}{3} $. Therefore, the general solutions in the second and third quadrants are:

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$ θ = \pi – \frac{\pi}{3} + 2k\pi = \frac{2\pi}{3} + 2k\pi $

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and

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$ θ = \pi + \frac{\pi}{3} + 2k\pi = \frac{4\pi}{3} + 2k\pi $

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where $ k $ is any integer.

Answer 2

Alex Thompson

William King

To find $ θ $ such that $ cos(θ) = -frac{1}{2} $, consider the reference angle $ frac{pi}{3} $. The cosine function is negative in the second and third quadrants:

$ θ = frac{2pi}{3} + 2kpi $

and

$ θ = frac{4pi}{3} + 2kpi $

where $ k $ is any integer.

Answer 3

Amelia Mitchell

Henry Green

Given $ cos(θ) = -frac{1}{2} $, the solutions are:

$ θ = frac{2pi}{3} + 2kpi $

and

$ θ = frac{4pi}{3} + 2kpi $

where $ k $ is any integer.