Unit Circle
Related Topics:
More Lessons for Trigonometry
Math Worksheets
The following diagram shows how the unit circle is related to sin, cos and tan. Scroll down the page for more examples and solutions on the unit circle, sine, cosine, and tangent.
In some other lessons, we have covered the three common trigonometry functions sine, cosine and tangent using the basic SOH-CAH-TOA definition.
More Lessons for Trigonometry
Math Worksheets
The following diagram shows how the unit circle is related to sin, cos and tan. Scroll down the page for more examples and solutions on the unit circle, sine, cosine, and tangent.
In some other lessons, we have covered the three common trigonometry functions sine, cosine and tangent using the basic SOH-CAH-TOA definition.
In this lesson, we will extend the definition of the trigonometry functions by using the unit circle.
A unit circle is a circle of radius one unit with its center at the origin.
Sine Function
As illustrated in the following diagram:
For a point (x, y) on the unit circle; sin θ = 
⇒ sin θ = y
Cosine Function
As illustrated in the following diagram:
For a point (x, y) on the unit circle; cos θ = 
⇒ cos θ = x
Tangent Function
As illustrated in the following diagram:
For a point (x, y) on the unit circle; tan θ = 
| Check out our most popular games! | ||
|---|---|---|
 Fraction Concoction |
 Fact Family Game |
 Number Bond Garden |
 Online Addition Subtraction Game |
 Penguin Solitaire |
 Sawayama Solitaire |
 Ark Solitaire |
 Eldritch Invasion |
 Shenzhen Solitaire |
Check out more Solitaire games here.
We welcome your feedback, comments and questions about this site or page. Please submit your feedback or enquiries via our Feedback page.