22 lines
1019 B
Markdown
22 lines
1019 B
Markdown
# Introduction
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The unit circle has a center a $(0, 0)$, and a radius of $1$ with no defined unit.
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Sine and cosine can be used to find the coordinates of specific points on the unit circle.
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**Sine likes $y$, and cosine likes $x$.**
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When sine is positive, the $y$ value is positive. When $x$ is positive, the cosine is positive.
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$$ cos(\theta) = x $$
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$$ sin(\theta) = y $$
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## The Pythagorean Identity
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The Pythagorean identity expresses the Pythagorean theorem in terms of trigonometric functions. It's a basic relation between the sine and cosine functions.
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$$ sin^2 \theta + cos^2 \theta = 1 $$
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# Definitions
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| Term | Description |
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| ---------------- | ----------------------------------------------------------------------------- |
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| $\theta$ (theta) | Theta refers to the angle measure in a unit circle. |
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| $s$ | $s$ is used to the length of the arc created by angle $\theta$ on the circle. | |