Thread: Condition Number of a Matrix

Compute the condition number of the following matrix:

| 1 1 |
| E -E |

where E<<l infinity norm.

My attempt:

A=
| 1 1 |
| E -E |

A^-1=
| 1 -E |
| -1 -E |

||A||infinity = max(2,0) = 2
||A^-1||infinity = max(1-E,-1-E) = 1-E

K(A) = 2(1-E) = 2-2E

Is K(A) correct or am I completely off? Any help is appreciated! Thanks!