With careful attention to branch cuts, the Wolfram Language supports trigonometric functions everywhere in the complex plane, with extensive exact and algebraic transformations, together with efficient arbitrary-precision numerical evaluation. The Wolfram Language follows the standard mathematical convention of using radians for trigonometric function arguments.

Sin  ▪  Cos  ▪  Tan  ▪  Csc  ▪  Sec  ▪  Cot

ArcSin  ▪  ArcCos  ▪  ArcTan  ▪  ArcCsc  ▪  ArcSec  ▪  ArcCot

Haversine  ▪  InverseHaversine

SinDegrees  ▪  CosDegrees  ▪  TanDegrees  ▪  CscDegrees  ▪  SecDegrees  ▪  CotDegrees

ArcSinDegrees  ▪  ArcCosDegrees  ▪  ArcTanDegrees  ▪  ArcCscDegrees  ▪  ArcSecDegrees  ▪  ArcCotDegrees

Degree (°) — constant to convert from radians to degrees

I () — , entered as ii ("imaginary i")

FromDMS, DMSList — convert between radians and degrees, minutes, seconds

AngleVector — generate a vector at a specified angle

CirclePoints — equally spaced points around a circle

ToPolarCoordinates  ▪  FromPolarCoordinates

FullSimplify — simplify trigonometric expressions

FunctionExpand — reduce to algebraic forms or simpler arguments

TrigExpand — Sin[2x]⟶2 Sin[x]Cos[x] etc.

TrigFactor — Sin[..]+Sin[..]⟶product of terms, etc.

TrigReduce — 2 Sin[x]Cos[x]⟶Sin[2x] etc.

TrigToExp, ExpToTrig — convert between trigonometric functions and exponentials

ComplexExpand — expand into real and imaginary parts