What it means
A circumflex over a letter. In statistics it marks an estimate, as in β̂ or ŷ, the fitted value. In physics it marks a unit vector, as in x̂, or a quantum operator, as in Ĥ.
Read aloud in real formulas
ŷ = β̂₀ + β̂₁x
Aethel says
y hat equals beta hat sub zero plus beta hat sub one x
the fitted regression line
Ĥψ = Eψ
Aethel says
H hat psi equals E psi
the Hamiltonian operator
Typing it
- LaTeX
- \hat{x}, \widehat{xy}
- Unicode
- U+0302
Formulas that use it
Questions
How do you say x̂ out loud?
It is usually read “hat”, and also “x hat”.
What does x̂ mean in maths?
A circumflex over a letter. In statistics it marks an estimate, as in β̂ or ŷ, the fitted value. In physics it marks a unit vector, as in x̂, or a quantum operator, as in Ĥ.
How do you type x̂?
In LaTeX, write \hat{x}, \widehat{xy}. Its Unicode code point is U+0302.