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Find the angle on the unit circle in the complex plane where the cosine value is $frac{1}{2}$

Answer 1

Abigail Nelson

Henry Green

We start by knowing that the cosine function gives the real part of the point on the unit circle corresponding to a given angle.

We are given $\cos(\theta) = \frac{1}{2}$ and need to find the angles $\theta$ where this holds true.

On the unit circle, $\cos(\theta)$ reaches $\frac{1}{2}$ at two points: $\theta = \frac{\pi}{3}$ and $\theta = \frac{5\pi}{3}$.

Therefore, the angles are:

$\theta = \frac{\pi}{3}, \frac{5\pi}{3}$

Answer 2

Alex Thompson

John Anderson

The cosine function represents the real part of complex numbers on the unit circle.

We have $cos( heta) = frac{1}{2}$, and we need to find the values of $ heta$ that satisfy this equation.

We know from trigonometry that $cos( heta) = frac{1}{2}$ at the angles:

$ heta = frac{pi}{3} + 2kpi quad ext{and} quad heta = -frac{pi}{3} + 2kpi$

where $k$ is any integer. For the interval $[0, 2pi)$, this simplifies to:

$ heta = frac{pi}{3}, frac{5pi}{3}$

Answer 3

Amelia Mitchell

Samuel Scott

The cosine function reflects the real part on the unit circle.

Given: $cos( heta) = frac{1}{2}$

Find $ heta$:

$ heta = pmfrac{pi}{3} + 2kpi$

Restricting to $[0, 2pi)$:

$ heta = frac{pi}{3}, frac{5pi}{3}$