Let $A$ be an $n\times n$ matrix. Recall that $C_{ij}$ is the $(i,j)$ [[cofactor]] of $A$. The **matrix of cofactors** of $A$ is the $n\times n$ matrix $C$ whose $(i,j)$ entry is $C_{ij}$.

The **adjoint** of $A$ is the $n\times n$ matrix $J=C^T$, the [[transpose]] of the matrix of cofactors.