@article{oai:kitami-it.repo.nii.ac.jp:00006195, author = {礒部, 煕郎 and 東山, 貞子}, issue = {1}, journal = {北見工業大学研究報告}, month = {Mar}, note = {application/pdf, Let A(x, x) be a quadratic form (with real coefficient) which corresponds to the symmetric matrix A=(aij). Namely, A(x, x)=Σaijx_ix_j. In this report, we assume that A is regular. The following theorem is well known : A(x, x) is positive definite form, if and only if, every principal minor of A is positive. We shall prove this theorem without taking up the Sylvester’s low of inertia and signature of A(x, x).}, pages = {109--113}, title = {実二次形式の符号について}, volume = {2}, year = {1967} }