---
title: 次方計算
tags: math, number theory
---

# 次方計算(Power Operation)

$e^x=\exp(x)=1+x+\cfrac{x^2}{2!}+\cfrac{x^3}{3!}+...$

by Binomial Expansion

$(1+x)^n = 1+nx+\cfrac{n(n-1)}{2!}x^2+\cfrac{n(n-1)(n-2)}{3!}x^3+...$