I have not come across this kind of problem, hence, not sure:(adsbygoogle = window.adsbygoogle || []).push({});

A is nxn, such that A^2 + 3A + I =0

show that A is invertible and A^(-1) = -A-3I

So far I have this:

-A^2 - 3A = I

but now I am not sure if I can factor out A:

(-1)A [A + 3] = I

because I do not think that A + 3 is defined for matrices, since 3 is a scalar and not actually a vector.

Any hints are very much appreciated.

**Physics Forums - The Fusion of Science and Community**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Related to inverses

Loading...

Similar Threads for Related inverses | Date |
---|---|

I Inverse of the sum of two matrices | Tuesday at 10:20 AM |

B How does matrix non-commutivity relate to eigenvectors? | Mar 28, 2018 |

A The meaning of the commutator for two operators | Jan 9, 2018 |

I Reflexive relation question | Oct 12, 2016 |

**Physics Forums - The Fusion of Science and Community**