For activities with important visual aids. Unit: Alg2.6 Trigonometric Functions (Algebra 2). Alg2.6 Trigonometric Functions In this unit, students are introduced to trigonometric functions. While they have studied a variety of function types with different key features previously, this is the first time students are asked to consider periodic functions, that is, functions whose output values repeat at regular intervals. Students first consider circular motion and learn to use right triangle trigonometry to identify the coordinates of a point on a circle. The unit circle is introduced, and students study the symmetry of its coordinates and reason about radian angles knowing a full circ