<p>设向量<img alt="" width="709" height="45" src="https://learnfile.20230611.cn/learnAppQuestion/98/85/9885cc70f64ed85186318be5a0823f84.png" style="width: 100%;height: auto;">, 则β 由<img alt="" width="145" height="34" src="https://learnfile.20230611.cn/l