Continuity of the determinant function

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SUMMARY

The discussion centers on proving the continuity of the determinant function, defined as ## \mbox{det}:\mbox{Mat}_{n\times n}(\mathbb{R}) \rightarrow \mathbb{R}##. The proof requires an epsilon-delta approach, with the understanding that ##\mbox{Mat}_{n\times n}(\mathbb{R})## can be identified with ##\mathbb{R}^{n^2}##. It is established that the determinant is a polynomial function of the entries of the matrix, which supports its continuity in the context of real numbers.

PREREQUISITES
  • Understanding of the determinant function in linear algebra
  • Familiarity with epsilon-delta definitions of continuity
  • Knowledge of polynomial functions and their properties
  • Basic concepts of matrix theory and real analysis
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  • Study epsilon-delta proofs in real analysis
  • Explore the properties of polynomial functions in multiple variables
  • Learn about continuity in the context of matrix functions
  • Investigate the implications of continuity for linear transformations
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Mathematicians, students of linear algebra, and anyone interested in the continuity of functions in real analysis.

dextercioby
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This is something I seek a proof of.

Theorem: Let ## \mbox{det}:\mbox{Mat}_{n\times n}(\mathbb{R}) \rightarrow \mathbb{R}## be the determinant function assigned to a general nxn matrix with real entries. Prove this mapping is continuous.

My attempt. Continuity must be judged in ##\mathbb{R}##, so it should eventually go down to an epsilon-delta proof. I was first thinking to identify ##\mbox{Mat}_{n\times n}(\mathbb{R}) = \mathbb{R}^{n^2}##. How do I go further?
 
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dextercioby said:
This is something I seek a proof of.

Theorem: Let ## \mbox{det}:\mbox{Mat}_{n\times n}(\mathbb{R}) \rightarrow \mathbb{R}## be the determinant function assigned to a general nxn matrix with real entries. Prove this mapping is continuous.

My attempt. Continuity must be judged in ##\mathbb{R}##, so it should eventually go down to an epsilon-delta proof. I was first thinking to identify ##\mbox{Mat}_{n\times n}(\mathbb{R}) = \mathbb{R}^{n^2}##. How do I go further?

Note that the determinant is a polynomial in the ##n^2## coordinates of ##R^{n^2}##. For instance for a ##R^4## it is ##xw-yz##.
 

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