# The condition number of matrix measures how close it is to being singular

Put content here**Definition:** The **condition number** of a nonsingular matrix $A$ is $\kappa(A) = \|A\| \cdot \|A^{-1}\|$. For the 2-norm, $\kappa(A) = \sigma_{\max}/\sigma_{\min}$ (ratio of largest to smallest singular value). A large condition number indicates the matrix is close to singular and numerical computations will be unstable.

# Parents

* Determinants