What it means
The eighth Greek letter. θ is the usual symbol for an angle and for the parameters of a statistical or machine-learning model. Capital Θ appears in Big-Theta notation for the growth rate of algorithms.
Read aloud in real formulas
sin²θ + cos²θ = 1
Aethel says
sin squared theta plus cos squared theta equals 1
θ is an angle
θ ← θ − η ∇L(θ)
Aethel says
theta is updated to theta minus eta times the gradient of L of theta
θ holds the model's parameters
T(n) = Θ(n log n)
Aethel says
T of n equals capital theta of n log n
grows at the rate n log n
Typing it
- LaTeX
- \theta, \vartheta, \Theta
- Unicode
- U+03B8, U+0398
Formulas that use it
Questions
How do you pronounce theta (θ)?
It is said “theta”, roughly THAY-tuh (US), THEE-tuh (UK).
What does θ mean in maths?
The eighth Greek letter. θ is the usual symbol for an angle and for the parameters of a statistical or machine-learning model. Capital Θ appears in Big-Theta notation for the growth rate of algorithms.
How do you type θ?
In LaTeX, write \theta, \vartheta, \Theta. Its Unicode code point is U+03B8, U+0398.