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Trigonometric functions

Connect periods, graphs, and sine/cosine amplitudes with rotation and repeated change.

Meaning

Defining cosine and sine using unit-circle coordinates extends them beyond acute angles. Sine and cosine repeat between -1 and 1; tangent is undefined where cosine is zero. One full turn returns to the same unit-circle point, so sine and cosine repeat every 2π. Multiplying sine by 2 doubles the vertical coordinate to a range from −2 to 2. Tangent is sin x/cos x, so it is undefined when the denominator is zero.

Example

Practice for this concept

Scope and references

Topics

Sine, cosine, tangent, periods, amplitudes, graphs

Learning goal

Connect periods, graphs, and sine/cosine amplitudes with rotation and repeated change.

Helpful background

Connect unit-circle angles with function inputs and outputs.

Trigonometric functions

These ordinary choice questions provide limited practice in this concept. They do not establish independent solution, full-concept performance, or mastery.