I have a question about matrices. I have the following symmetric matrix
$$\begin{bmatrix} 2 & -1 & 0\\ -1 & 1 & -1\\ 0 & -1 & 1\end{bmatrix}$$
The first leading minor is positive. The second as well, but the third is negative. Is it now the case that this matrix is indefinite?
Thanks for your profound help!