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

Trigonometric Functions

Extend the domain of trigonometric functions using the unit circle.