Lesson 4: 4.4 Trigonometric Functions of Any Angle

How do you evaluate trigonometric functions of any angle?

reference angle

TF. A. 3. Use special triangles to determine geometrically the values of sine, cosine, tangent for p/3, p/4 and p/6, and use the unit circle to express the values of sine, cosine, and tangent for x, p + x, and 2p – x in terms of their values for x, where x is any real number.

Use Khan Academy resources.

Students will use their prior knowledge of the six trigonometric functions to learn how to evaluate those functions for any angle measure.

You can use trigonometric functions to model and solve real-life problems. For instance, trigonometric functions can be used to model the monthly sales of a seasonal product, such as wakeboards.

Some students incorrectly think that a quotient with zero in the denominator is equal to zero instead of being undefined.
Some students may forget to use the quadrant in which the angle theta lies to determine the sign of the function value.

Students may benefit from using a mnemonic to remember the trigonometric functions with positive signs for Quadrants I through IV, such as All Students Take Calculus or CAST.

Use common assessments.

Pre-Calculus with Limits resources.