<p>若实二次型<img max-width="300" src="https://learnfile.20230611.cn/learnAppQuestion/82/fd/82fd73ac8f26fe5e9930dc3fa00ab940.jpg" style="width: 100%;height: auto;">正定，则数<img max-width="300" src="https://learnfile.20230611.cn/learnAppQuestion/d4/3d/d43d5fb