Linear maps, inverses and associated matrices?

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This is likely a very simple question but if we have a linear map $f$ with an associated matrix $A$ is it a necessary and sufficient condition that for $f$ to have an inverse then $A$ must also have an inverse?

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Yes, the map $f$ has an inverse if and only if the matrix representing $f$ has an inverse.

This is quite easy to prove, if the matrix $A$ is invertible then the inverse of $f$ is the map $x \mapsto A^{-1}x$. Conversely if $f$ has an inverse then the inverse of $A$ is the matrix associated to $f^{-1}$.