Trigonometry Calculator

Calculate trigonometric functions with detailed explanations and visualizations

Trigonometric Functions

Trigonometric Results

45°=0.000000 rad
Sine(45°)

Enter an angle to calculate the trigonometric function

Understanding Trigonometry

What is Trigonometry?

Trigonometry is the branch of mathematics that deals with the relationships between the sides and angles of triangles. The word comes from Greek "trigonon" meaning "triangle" and "metron" meaning "measure".

Basic Trigonometric Ratios:

sin(θ) = opposite/hypotenuse

cos(θ) = adjacent/hypotenuse

tan(θ) = opposite/adjacent

These ratios are defined for right-angled triangles

Unit Circle

The unit circle is a circle with radius 1 centered at the origin. It's fundamental to understanding trigonometric functions as they relate angles to coordinates on this circle.

  • Coordinates: (cos θ, sin θ) for angle θ
  • Periodicity: Functions repeat every 360° or 2π radians
  • Quadrants: Signs of functions change in different quadrants
  • Radians: Natural unit for angles in calculus

Special Angles

AngleRadianssincostan
0°0.0000010
30°0.52360.50.8660250.57735
45°0.78540.7071070.7071071
60°1.04720.8660250.51.732051
90°1.570810
180°3.14160-10
270°4.7124-10
360°6.2832010

Real-World Applications

Physics

Motion and forces

  • • Projectile motion
  • • Wave motion
  • • Oscillations
  • • Circular motion

Engineering

Design and analysis

  • • Structural analysis
  • • Signal processing
  • • Control systems
  • • Mechanical design

Navigation

Position and direction

  • • GPS coordinates
  • • Bearing calculations
  • • Course plotting
  • • Astronomy

Computer Graphics

3D rendering

  • • 3D rotations
  • • Camera projections
  • • Animation
  • • Game physics

Architecture

Building design

  • • Roof slopes
  • • Structural angles
  • • Surveying
  • • Construction

Music

Sound waves

  • • Sound synthesis
  • • Acoustics
  • • Harmonics
  • • Audio engineering

Trigonometric Identities

Fundamental Identities

Pythagorean Identity

sin²θ + cos²θ = 1

Reciprocal Identities

cscθ = 1/sinθ, secθ = 1/cosθ, cotθ = 1/tanθ

Quotient Identities

tanθ = sinθ/cosθ, cotθ = cosθ/sinθ

Angle Sum and Difference

Sum Formulas

sin(α±β) = sinα cosβ ± cosα sinβ

cos(α±β) = cosα cosβ ∓ sinα sinβ

Product Formulas

sinα sinβ = ½[cos(α-β) - cos(α+β)]

cosα cosβ = ½[cos(α-β) + cos(α+β)]

Double Angle Formulas

sin(2θ) = 2sinθ cosθ

Double angle for sine

cos(2θ) = cos²θ - sin²θ = 2cos²θ - 1 = 1 - 2sin²θ

Double angle for cosine

tan(2θ) = 2tanθ/(1 - tan²θ)

Double angle for tangent

Inverse Trigonometric Functions

Definition and Domain

Inverse trigonometric functions find the angle when the trigonometric ratio is known. They are denoted with arc- prefix.

arcsin(x) = sin⁻¹(x)

Domain: [-1, 1], Range: [-π/2, π/2]

arccos(x) = cos⁻¹(x)

Domain: [-1, 1], Range: [0, π]

arctan(x) = tan⁻¹(x)

Domain: (-∞, ∞), Range: (-π/2, π/2)

Common Values

arcsin(1/2) = π/6 (30°)

arcsin(√2/2) = π/4 (45°)

arccos(1/2) = π/3 (60°)

arccos(√2/2) = π/4 (45°)

arctan(1) = π/4 (45°)

arctan(√3) = π/3 (60°)