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Find the cosine and sine of an angle on the unit circle

Answer 1

Abigail Nelson

Lily Perez

Given an angle $\theta = \frac{5\pi}{6}$ radians, find the coordinates $(\cos \theta, \sin \theta)$ on the unit circle.

Step 1: Recognize that $\theta = \frac{5\pi}{6}$ is an angle in the second quadrant.

Step 2: In the second quadrant, cosine is negative and sine is positive.

Step 3: Use the reference angle, which is $\pi – \frac{5\pi}{6} = \frac{\pi}{6}$.

Step 4: Recall the sine and cosine values for $\frac{\pi}{6}$: $\sin \frac{\pi}{6} = \frac{1}{2}$ and $\cos \frac{\pi}{6} = \frac{\sqrt{3}}{2}$.

Step 5: Apply the signs for the second quadrant: $\cos \frac{5\pi}{6} = -\cos \frac{\pi}{6} = -\frac{\sqrt{3}}{2}$ and $\sin \frac{5\pi}{6} = \sin \frac{\pi}{6} = \frac{1}{2}$.

Thus, the coordinates are $\left(-\frac{\sqrt{3}}{2}, \frac{1}{2}\right)$.

Answer 2

Alex Thompson

Amelia Mitchell

Given $ heta = frac{5pi}{6}$, find $(cos heta, sin heta)$ on the unit circle.

1. $frac{5pi}{6}$ lies in the second quadrant.

2. Reference angle: $frac{pi}{6}$.

3. Values in the first quadrant: $cos frac{pi}{6} = frac{sqrt{3}}{2}$, $sin frac{pi}{6} = frac{1}{2}$.

4. Adjust for the second quadrant: $cos frac{5pi}{6} = -frac{sqrt{3}}{2}$, $sin frac{5pi}{6} = frac{1}{2}$.

Coordinates: $left(-frac{sqrt{3}}{2}, frac{1}{2}
ight)$

Answer 3

Amelia Mitchell

Alex Thompson

For $ heta = frac{5pi}{6}$, find $(cos heta, sin heta)$ on the unit circle.

Second quadrant: $cos = -frac{sqrt{3}}{2}$, $sin = frac{1}{2}$.

Coordinates: $left(-frac{sqrt{3}}{2}, frac{1}{2}
ight)$