Graphs of Trigonometric Functions & Trigonometric Identities

The sine function, denoted as sin(x), is a trigonometric function that represents the ratio of the length of the opposite side to the hypotenuse in a right triangle.

The cosine function, denoted as cos(x), is a trigonometric function that represents the ratio of the length of the adjacent side to the hypotenuse in a right triangle.

The tangent function, denoted as tan(x), is a trigonometric function that represents the ratio of the sine to the cosine of an angle, or tan(x) = sin(x)/cos(x).

The cosecant function, denoted as csc(x), is the reciprocal of the sine function: csc(x) = 1/sin(x).

The secant function, denoted as sec(x), is the reciprocal of the cosine function: sec(x) = 1/cos(x).

The cotangent function, denoted as cot(x), is the reciprocal of the tangent function: cot(x) = 1/tan(x).

The Pythagorean identity states that sin²(x) + cos²(x) = 1 for any angle x.

sin(x) * sec(x) = tan(x).

cos(x) * tan(x) = sin(x).

tan(x) * csc(x) * cos(x) = 1.