Arcsin arccos arctan

Math

Definition

The inverse trigonometric functions that return an angle given a ratio. arcsin(x) returns the angle whose sine is x, arccos(x) returns the angle whose cosine is x, and arctan(x) returns the angle whose tangent is x. Each has a restricted range to ensure it is a function.

Examples

  • arcsin(1/2) = π/6 (or 30°) because sin(30°) = 1/2
  • arctan(1) = π/4 (or 45°) because tan(45°) = 1
Key Fact

arcsin: [−π/2, π/2], arccos: [0, π], arctan: (−π/2, π/2)

Related Terms

Evaluating inverse trig Compositions of inverse trig Unit circle values Soh-cah-toa

Study This Concept

Practice arcsin arccos arctan with free review games in these units:

Trigonometry Unit 6: Inverse Trig Functions