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# Trigonometry

Introduction to the trigonometric ratios: Trigonometry with right trianglesSolving for a side in a right triangle using the trigonometric ratios: Trigonometry with right trianglesSolving for an angle in a right triangle using the trigonometric ratios: Trigonometry with right trianglesModeling with right triangles: Trigonometry with right triangles

Trigonometric ratios and similarity: Trigonometry with right trianglesSine and cosine of complementary angles: Trigonometry with right trianglesTrigonometric ratios of special triangles: Trigonometry with right trianglesIntroduction to the Pythagorean trigonometric identity: Trigonometry with right trianglesThe reciprocal trigonometric ratios: Trigonometry with right triangles

Introduction to radians: The unit circle definition of sine, cosine, and tangentThe unit circle definition of sine, cosine, and tangent: The unit circle definition of sine, cosine, and tangentThe graphs of sine, cosine, and tangent: The unit circle definition of sine, cosine, and tangent

Basic trigonometric identities: The unit circle definition of sine, cosine, and tangentTrigonometric values of special angles: The unit circle definition of sine, cosine, and tangentThe Pythagorean identity: The unit circle definition of sine, cosine, and tangentLong live Tau: The unit circle definition of sine, cosine, and tangent

The inverse trigonometric functions: Trigonometric equations and identitiesSolving basic sinusoidal equations: Trigonometric equations and identitiesSolving advanced sinusoidal equations: Trigonometric equations and identities

Solving sinusoidal models: Trigonometric equations and identitiesIntroduction to the trigonometric angle addition identities: Trigonometric equations and identitiesUsing trigonometric identities to solve problems: Trigonometric equations and identitiesChallenging trigonometry problems: Trigonometric equations and identities

Test your knowledge of the skills in this course. Have a test coming up? The Course challenge can help you understand what you need to review.

## Review articles

## Get StartedIntroduction to the trigonometric ratios

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

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