Interactive Unit Circle Visualizer
A dynamic visualization of the Unit Circle. Understand the relationship between angles (degrees/radians) and the corresponding sin, cos, and tan values at key points. Features interactive controls and displays all six trigonometric function values.
About Interactive Unit Circle Visualizer
Welcome to our Interactive Unit Circle Visualizer, an educational tool designed to help you understand the fundamental relationships between angles and trigonometric functions. This dynamic visualization shows how sin, cos, tan, and their reciprocal functions relate to points on the unit circle.
What is the Unit Circle?
The unit circle is a circle with a radius of 1, centered at the origin (0, 0) of the coordinate plane. It is the foundation of trigonometry and provides a geometric interpretation of the trigonometric functions.
- Radius: Always equals 1
- Center: Located at the origin (0, 0)
- Equation: $$x^2 + y^2 = 1$$
Trigonometric Functions on the Unit Circle
For any angle $\theta$ measured from the positive x-axis, a point P on the unit circle has coordinates:
$$P = (\cos\theta, \sin\theta)$$The Six Trigonometric Functions
- Sine (sin): $$\sin\theta = y$$ (the y-coordinate of the point)
- Cosine (cos): $$\cos\theta = x$$ (the x-coordinate of the point)
- Tangent (tan): $$\tan\theta = \frac{\sin\theta}{\cos\theta} = \frac{y}{x}$$
- Cosecant (csc): $$\csc\theta = \frac{1}{\sin\theta}$$ (undefined when $\sin\theta = 0$)
- Secant (sec): $$\sec\theta = \frac{1}{\cos\theta}$$ (undefined when $\cos\theta = 0$)
- Cotangent (cot): $$\cot\theta = \frac{\cos\theta}{\sin\theta} = \frac{1}{\tan\theta}$$
Key Angles and Their Values
The unit circle has several important angles that you should memorize. These "special angles" occur at multiples of 30 and 45 degrees:
| Degrees | Radians | sin | cos | tan |
|---|---|---|---|---|
| 0 | 0 | 0 | 1 | 0 |
| 30 | $\frac{\pi}{6}$ | $\frac{1}{2}$ | $\frac{\sqrt{3}}{2}$ | $\frac{\sqrt{3}}{3}$ |
| 45 | $\frac{\pi}{4}$ | $\frac{\sqrt{2}}{2}$ | $\frac{\sqrt{2}}{2}$ | 1 |
| 60 | $\frac{\pi}{3}$ | $\frac{\sqrt{3}}{2}$ | $\frac{1}{2}$ | $\sqrt{3}$ |
| 90 | $\frac{\pi}{2}$ | 1 | 0 | Undefined |
| 180 | $\pi$ | 0 | -1 | 0 |
| 270 | $\frac{3\pi}{2}$ | -1 | 0 | Undefined |
The Four Quadrants
The coordinate plane is divided into four quadrants, and the signs of trigonometric functions vary by quadrant:
- Quadrant I (0-90): All functions positive (A)
- Quadrant II (90-180): Only sin and csc positive (S)
- Quadrant III (180-270): Only tan and cot positive (T)
- Quadrant IV (270-360): Only cos and sec positive (C)
Remember: ASTC - "All Students Take Calculus"
How to Use This Tool
- Enter an angle value in the input field
- Select whether the angle is in degrees or radians
- Click "Calculate" to see the visualization and all trigonometric values
- Use the quick-select links for common angles
Understanding the Visualization
The interactive diagram shows:
- Blue circle: The unit circle with radius 1
- Red dot: The point on the circle corresponding to your angle
- Green line: Represents cos (horizontal distance from origin)
- Blue line: Represents sin (vertical distance from origin)
- Orange line: The angle arc from the positive x-axis
- Dashed purple line: Represents the tangent line
Applications of the Unit Circle
- Physics: Wave motion, oscillations, circular motion
- Engineering: Signal processing, AC circuits, rotational mechanics
- Computer Graphics: Rotations, animations, game development
- Navigation: GPS calculations, surveying
- Music: Sound wave analysis, audio synthesis
Additional Resources
Reference this content, page, or tool as:
"Interactive Unit Circle Visualizer" at https://MiniWebtool.com// from MiniWebtool, https://MiniWebtool.com/
by miniwebtool team. Updated: Nov 23, 2025
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