{ "cells": [ { "attachments": {}, "cell_type": "markdown", "metadata": {}, "source": [ "### 二変数関数 $f(x, y)$ の二階偏導関数\n", "\n" ] }, { "attachments": {}, "cell_type": "markdown", "metadata": {}, "source": [ "### Step 1: 二変数関数の微分\n", "\n", "$$\n", "\\begin{align*}\n", "&f(x,y) \\equiv \\frac{n!}{a! b! (n-a-b)!} x^a (y-x)^b (1-y)^{n-a-b}\\\\\n", "&\\text{want to show}\\Rightarrow\\frac{\\partial f(x, y)}{\\partial x\\partial y}\n", "\\end{align*}\n", "$$\n", "\n", "\n" ] }, { "cell_type": "code", "execution_count": 2, "metadata": { "vscode": { "languageId": "python" } }, "outputs": [ { "data": { "text/html": [ "
\left\{\frac{a b n! x^{a-1} (y-x)^{b-1} (1-y)^{-a-b+n}}{a! b! (-a-b+n)!}-\frac{a n!\
> x^{a-1} (-a-b+n) (y-x)^b (1-y)^{-a-b+n-1}}{a! b! (-a-b+n)!}-\frac{(b-1) b n! x^a\
> (y-x)^{b-2} (1-y)^{-a-b+n}}{a! b! (-a-b+n)!}+\frac{b n! x^a (-a-b+n) (y-x)^{b-1}\
> (1-y)^{-a-b+n-1}}{a! b! (-a-b+n)!}\right\}