← Mathematical compendium

Published equation contexts

κ(A)=∥A∥ ∥A−1∥\kappa(A) = \|A\| \, \|A^{-1}\|

Why this formula appears here

Numerical analysis has always run on an analogous verification principle, just usually informal: an error bound is only useful if it is derived from and checkable against a stated model of arithmetic. The classical example is the sensitivity of a linear system to input error, captured by the condition number of a matrix A : κ(A)=∥A∥ ∥A−1∥\kappa(A) = \|A\| \, \|A^{-1}\|. If κ(A)\kappa(A) is large, small errors in the input data or in floating-point rounding can produce large errors in the computed solution, independent of which algorithm is used to solve the system — a property of the problem, not the solver. Bringing formal verification to numerical software means proving that an implementation’s actual rounding behavior…

Read the full article-specific guide →

Read the representative guide

How to interpret it

Read it with the definitions, units, and assumptions supplied by the article.

Research cited beside this formula

Published contexts (1)

A symbol can carry a different meaning in another article. Each occurrence keeps its own guide and term definitions.

κ(A)=∥A∥ ∥A−1∥\kappa(A) = \|A\| \, \|A^{-1}\|

Equation 6 · Mathematics

Mathematics, Proof, and Scientific Computation in 2035: Scenarios, Signals, and Falsifiable Predictions

This equation states an equality: the expressions on both sides have the same value under the article’s assumptions.

Numerical analysis has always run on an analogous verification principle, just usually informal: an error bound is only useful if it is derived from and checkable against a stated model of arithmetic. The classical example is the sensitivity of a linear system to input error, captured by the condition number of a matrix A : κ(A)=∥A∥ ∥A−1∥\kappa(A) = \|A\| \, \|A^{-1}\|. If κ(A)\kappa(A) is large, small errors in the input data or in floating-point rounding can produce large errors in the computed solution, independent of which algorithm is used to solve the system — a property of the problem, not the solver. Bringing formal verification to numerical software means proving that an implementation’s actual rounding behavior…

Equation guide → · Article →