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Main content

The unit circle definition of sine, cosine, and tangent

Introduction to radians

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Intro to radiansRadians & degreesDegrees to radiansRadians to degreesRadian angles & quadrants

Practice

Radians & degreesGet 3 of 4 questions to level up!

The unit circle definition of sine, cosine, and tangent

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Unit circleThe trig functions & right triangle trig ratiosTrig unit circle review

The graphs of sine, cosine, and tangent

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Graph of y=sin(x)Graph of y=tan(x)Intersection points of y=sin(x) and y=cos(x)

Basic trigonometric identities

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Sine & cosine identities: symmetryTangent identities: symmetrySine & cosine identities: periodicityTangent identities: periodicity

Trigonometric values of special angles

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Trig values of special angles

Practice

Trig values of special anglesGet 3 of 4 questions to level up!

The Pythagorean identity

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Proof of the Pythagorean trig identityUsing the Pythagorean trig identityPythagorean identity review

Practice

Use the Pythagorean identityGet 3 of 4 questions to level up!

Long live Tau

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Tau versus piPi is (still) wrong

About this unit

Learn how the trigonometric ratios are extended to all real numbers using algebra. Start solving simple problems that involve this new definition of the trigonometric functions.