<p>设P为正交矩阵，向量<img src="https://file.gaojiufeng.cn/learnAppQuestion/fc/ab/fcabb70e5e2f7018bb51edd6e46e24cb.jpg" style="width: 100%;height: auto;">，<img src="https://file.gaojiufeng.cn/learnAppQuestion/5f/30/5f3000bdc45aa94cca9b00057141af89.jpg" style="width: 100%;height: auto;">的内积（<img src="https://file.gaojiufeng.cn/learnAppQuestion/fc/ab/fcabb70e5e2f7018bb51edd6e46e24cb.jpg" style="width: 100%;height: auto;">，<img src="https://file.gaojiufeng.cn/learnAppQuestion/5f/30/5f3000bdc45aa94cca9b00057141af89.jpg" style="width: 100%;height: auto;">）＝2，则（<img src="https://file.gaojiufeng.cn/learnAppQuestion/11/9d/119dea6a7f118481f5125ae9cfe3aa03.jpg" style="width: 100%;height: auto;">，<img src="https://file.gaojiufeng.cn/learnAppQuestion/c9/69/c969af3c90399eec7e852acad4fdd580.jpg" style="width: 100%;height: auto;">）＝</p>