How to solve
At angle θ, the point on the unit circle is P = (cos θ, sin θ). The horizontal coordinate is cosine; the vertical coordinate is sine.
Steps
- Locate θ and its quadrant.
- Recall the reference-angle coordinate pair.
- Apply the correct signs for the quadrant.
Example
θ = 2π/3.
- Reference angle π/3 gives (1/2, √3/2).
- Quadrant II makes x negative.
Answer: (−1/2, √3/2)
How to type answers
- Use sqrt(n), e.g. -1/2 or sqrt(3)/2
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