☰
Home
Featured Topics
CLICK ANYWHERE TO CLOSE
Algebra
Calculus
Trigonometry
Combinatorics
Linear Algebra
Probability
Mathematical Logic
Set Theory
Sequences
Complex Numbers
Arithmetic
Functions
Definitions
Equations
Formulas
Identities
Inequalities
Logarithms
Polynomials
Powers
Roots
Visual Tools
Resources
CLICK ANYWHERE TO CLOSE
Visual Tools
Calculators
Solvers
Generators
Converters
Tables
Other Tools
Base Converter
Binomial
Cdf
Chebyshev
Coin Toss
Conditional Probability
Conditional Probability - Contingency Table
Conditional Probability - Tree Diagram
Conditional Probability - Venn Diagram
Conditional Probability - Waffle Chart
Contingency Tables
Continuous
Continuous
Determinant Calculator
Dice Roll
Discrete
Discrete
Discrete
Distributions
Expected Value
Exponential
Fractions Visualizer
Gauss Elimination
Geometric
Hypergeometric
Inequalities
Markov
Matrix Multiplication
Matrix Transposition
Matrix Types
Negative Binomial
Normal
Permutations Visualizer
Poisson
Probability Function
Square Root
Total Probability
Tree Builder
Uniform Continuous
Uniform Discrete
Unit Circle
Variance
Venn Diagrams
Venn Diagrams - Three Sets
Venn Diagrams - Two Sets
Weighted
Go Back
Visual Tools
Calculators
Tables
Mathematical Keyboard
Converters
Other Tools
Home
trigonometry
visual-tools
double-angle-identities
Double Angle Trigonometric Identities
sin
(2θ)
cos
(2θ)
tan
(2θ)
csc
(2θ)
sec
(2θ)
cot
(2θ)
sin
(
2θ
) =
2
sin θ
·
cos θ
θ
35°
Bisected apex scene
O
A
B
M
a = 1
b = 1
C = 2θ
θ
θ
cos θ
sin θ
sin θ
Reset
‹ Prev
Play
Next ›
0.5×
1×
1.5×
2×
Step 0 of 6
sin(2θ)
0.940
2 sin θ cos θ
0.940
Derivation
Press Play to step through the proof.
Function
Identity
Value
Source
sin
(2θ)
= 2 sin θ · cos θ
0.940
geometric
cos
(2θ)
= 1 − 2 sin²θ
0.342
geometric
tan
(2θ)
= 2 tan θ / (1 − tan²θ)
2.747
via
sin
,
cos
csc
(2θ)
= 1 / (2 sin θ · cos θ)
1.064
via
sin
sec
(2θ)
= 1 / (1 − 2 sin²θ)
2.924
via
cos
cot
(2θ)
= (1 − tan²θ) / (2 tan θ)
0.364
via
tan