Pythagorean Identity: The Pythagorean Identity is a specific trigonometric identity that relates the squares of sine and cosine functions. It states that sin^2(x) + cos^2(x) = 1.
Double Angle Identities: Double angle identities are trigonometric identities that express the values of sine, cosine, and tangent functions when the angle is doubled. They are useful in simplifying expressions involving double angles.
Reciprocal Identities: Reciprocal identities are trigonometric identities that relate the reciprocal values of sine, cosine, and tangent functions to their original values. For example, sin(x) = 1/csc(x), cos(x) = 1/sec(x), and tan(x) = 1/cot(x).