The unit circle definition of sine, cosine, and tangent

Progress
Introduction to radians
The unit circle definition of sine, cosine, and tangent
The graphs of sine, cosine, and tangent
Basic trigonometric identities
Trigonometric values of special angles
The Pythagorean identity
Long live Tau
Unit test
10 questions
Lessons
Introduction to radiansThe unit circle definition of sine, cosine, and tangentThe graphs of sine, cosine, and tangentBasic trigonometric identitiesTrigonometric values of special anglesThe Pythagorean identityLong live TauUnit test
Introduction to radians
Learn
Intro to radians
Radians & degrees
Degrees to radians
Radians to degrees
Radian angles & quadrants
Practice
Radians & degrees
4 questions
Try again
The unit circle definition of sine, cosine, and tangent
Learn
Unit circle
The trig functions & right triangle trig ratios
Trig unit circle review
The graphs of sine, cosine, and tangent
Learn
Graph of y=sin(x)
Graph of y=tan(x)
Intersection points of y=sin(x) and y=cos(x)
Basic trigonometric identities
Learn
Sine & cosine identities: symmetry
Tangent identities: symmetry
Sine & cosine identities: periodicity
Tangent identities: periodicity
Trigonometric values of special angles
Learn
Trig values of special angles
Practice
Trig values of special angles
4 questions
Practice
The Pythagorean identity
Learn
Proof of the Pythagorean trig identity
Using the Pythagorean trig identity
Pythagorean identity review
Practice
Use the Pythagorean identity
4 questions
Practice
Long live Tau
Learn
Tau versus pi
Pi is (still) wrong
Unit test
Test your understanding of The unit circle definition of sine, cosine, and tangent with these 10 questions.

It takes about 15 to 20 minutes to finish this test.