LaTeX hat symbol (hat, widehat, widecheck)

Symbol Command
$\hat{a}$ \hat{a}
$\hat{\alpha}$ \hat{\alpha}
$\hat{abc}$ \hat{abc}
$\widehat{abc}$ \widehat{abc}
$\widehat{vector}$ \widehat{\vector}
$\widecheck{abc}$ \widehat{abc}
$\widecheck{vector}$ \widehat{\vector}

LaTeX symbol

LaTeX