广义二项式

<p><img src="https://www.showdoc.com.cn/server/api/attachment/visitfile/sign/088406ce02a3437e43f2786d9a1b0f73" alt="" /> 广义二项式常常用于生成函数展开，特殊的 <img src="https://www.showdoc.com.cn/server/api/attachment/visitfile/sign/2391cfc43a27d767b68663fffc7278ce" alt="" /></p> <pre><code>$$(x+y)^n=\sum\limits_{k=0}^nC_{n}^{k}x^{n-k}y^k$$ $$\frac{1}{(1-x)^n}=\sum\limits_{i=0}^{\infty}C_{n+i-1}^ix^i$$</code></pre>