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Trigonometry

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Trigonometry with right triangles

Introduction to the trigonometric ratiosSolving for a side in a right triangle using the trigonometric ratiosSolving for an angle in a right triangle using the trigonometric ratiosModeling with right triangles

Trigonometric ratios and similaritySine and cosine of complementary anglesTrigonometric ratios of special trianglesIntroduction to the Pythagorean trigonometric identityThe reciprocal trigonometric ratios

Trigonometry with general triangles

The law of sinesThe law of cosinesSolving general triangles

The unit circle definition of sine, cosine, and tangent

Introduction to radiansThe unit circle definition of sine, cosine, and tangentThe graphs of sine, cosine, and tangent

Basic trigonometric identitiesTrigonometric values of special anglesThe Pythagorean identityLong live Tau

Graphs of trigonometric functions

The graphs of sine, cosine, and tangentIntroduction to amplitude, midline, and extrema of sinusoidal functionsFinding amplitude and midline of sinusoidal functions from their formulas

Period of sinusoidal functionsGraphing sinusoidal functionsConstructing sinusoidal functions

Trigonometric equations and identities

The inverse trigonometric functionsSolving basic sinusoidal equationsSolving advanced sinusoidal equations

Solving sinusoidal modelsIntroduction to the trigonometric angle addition identitiesUsing trigonometric identities to solve problemsChallenging trigonometry problems

Staff picks

Trig identity reference

Using trigonometric identities to solve problems

Proof of the law of sines

The law of sines

The unit circle definition of sine, cosine, and tangent

Solve for a side in right triangles

Solving for a side in a right triangle using the trigonometric ratios

Graph of y=sin(x)

The graphs of sine, cosine, and tangent

Review articles

Trig unit circle review

The unit circle definition of sine, cosine, and tangent

Laws of sines and cosines review

Solving general triangles

Pythagorean identity review

The Pythagorean identity

Midline, amplitude, and period review

Period of sinusoidal functions

Trigonometric ratios review

The reciprocal trigonometric ratios

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Introduction to the trigonometric ratios

Meet your new best friends: sine, cosine, and tangent.

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