Radian measure of an angle

2π radians in a revolution

Arc length and area of a sector of a circle

${\displaystyle l=r\theta \;}$

${\displaystyle A={\frac {1}{2}}r^{2}\theta }$

• Where θ is in radians

Area of a segment of a circle

Definitions of trigonometric functions

In mathematics, the trigonometric functions (also called circular functions) are functions of an angle. They are used to relate the angles of a triangle to the lengths of the sides of a triangle. Trigonometric functions are important in the study of triangles and modeling periodic phenomena, among many other applications.

Symmetry properties of trigonometric functions

Some exact values

Graphs of trigonometric functions

Graphs of y = a sin bx and y = a cos bx

Graphs of y = a sin b(x + c) and y = a cos b(x + c)

Graphical solution of equations

Derivative of sin x and cos x

${\displaystyle \sin 'x=\cos x\;}$

${\displaystyle \cos 'x=-\sin x\;}$

Derivative of tan x

${\displaystyle \tan 'x=\sec ^{2}x\;}$

Derivative of sin (ax + b)

${\displaystyle \sin '(ax+b)=a\cos(ax+b)\;}$

Derivative of cos (ax + b)

${\displaystyle \cos '(ax+b)=-a\sin(ax+b)\;}$

Functions defined by integrals (indefinite integrals)

Primitives of trigonometric functions