unit circle
What unit circle means in Mathematics A-Level, as defined for Pearson Edexcel, WJEC.
Definitions of unit circle
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Reference: WJEC
The circle x² + y² = 1 centred at the origin, used to define trigonometric ratios for any real angle θ.
The circle x² + y² = 1, where x = cos θ and y = sin θ.
A circle of radius 1 centred at the origin; at angle θ its point has coordinates `(cos θ, sin θ)`.
Topics that use unit circle
- Trigonometry (Pearson Edexcel A-Level)
- Trigonometry (AS Unit 1: Pure Mathematics A) (WJEC A-Level)
Related terms
- area of a triangle
- principal value
- Arcsin, arccos and arctan
- Asymptotes
- CAST diagram
- cosine rule
- Domain
- Domains of reciprocal functions
Using unit circle in the exam
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