<p>设随机变量石的概率密度<img style="width: 100%;height: auto;" data-cke-saved-src="https://learnfile.20230611.cn/img/201905251113580b12a2d619e9020833b9bc0a9899344f.png" src="https://learnfile.20230611.cn/learnAppQuestion/81/0e/810ec9c10eb0bf8be644c8bdd5828dae.