# Math Help - Quick question about matrices

1. ## Quick question about matrices

If a matrix is positive definite then does this imply that this matrix is non-singular? if so why?

2. Originally Posted by mbbx5va2
If a matrix is positive definite then does this imply that this matrix is non-singular? if so why?
Yes.

Read this: Topic 4.2: Positive-Definite Matrices (Theorem 4.2.2)

3. Originally Posted by mr fantastic
Originally Posted by mbbx5va2
If a matrix is positive definite then does this imply that this matrix is non-singular? if so why?
Yes.

Read this: Topic 4.2: Positive-Definite Matrices (Theorem 4.2.2)
But be aware that some people use "positive definite" to mean "positive semi-definite", in which case the matrix might be singular.

4. Thanks for the replies!