学習環境
- Surface 3 (4G LTE)、Surface 3 タイプ カバー、Surface ペン(端末)
- Windows 10 Pro (OS)
- Nebo(Windows アプリ)
- iPad Pro + Apple Pencil
- MyScript Nebo(iPad アプリ)
- 参考書籍
解析入門 原書第3版 (S.ラング(著)、松坂 和夫(翻訳)、片山 孝次(翻訳)、岩波書店)の第2部(微分と基本的な関数)、第8章(指数関数と対数関数)、4(大きさの程度)、練習問題14.を取り組んでみる。
x が0ではない場合の導関数は、常に
という 形になり、
となるので、0においてさらに高次の微分係数をもっていて、その値は0である。
コード(Emacs)
Python 3
#!/usr/bin/env python3
from sympy import pprint, symbols, exp, Derivative, Limit
x = symbols('x')
f = exp(-1 / x ** 2)
for n in range(2, 5):
D = Derivative(f, x, n)
fn = D.doit()
for t in [D, fn]:
pprint(t)
print()
for dir in ['+', '-']:
l = Limit(fn, x, 0, dir=dir)
for t in [l, l.doit()]:
pprint(t)
print()
print()
入出力結果(Terminal, Jupyter(IPython))
$ ./sample14.py
⎛ -1 ⎞
⎜ ───⎟
2⎜ 2⎟
d ⎜ x ⎟
───⎝ℯ ⎠
2
dx
-1
───
2
⎛ 2 ⎞ x
2⋅⎜-3 + ──⎟⋅ℯ
⎜ 2⎟
⎝ x ⎠
────────────────
4
x
⎛ -1 ⎞
⎜ ───⎟
⎜ 2⎟
⎜ ⎛ 2 ⎞ x ⎟
⎜2⋅⎜-3 + ──⎟⋅ℯ ⎟
⎜ ⎜ 2⎟ ⎟
⎜ ⎝ x ⎠ ⎟
lim ⎜────────────────⎟
x─→0⁺⎜ 4 ⎟
⎝ x ⎠
0
⎛ -1 ⎞
⎜ ───⎟
⎜ 2⎟
⎜ ⎛ 2 ⎞ x ⎟
⎜2⋅⎜-3 + ──⎟⋅ℯ ⎟
⎜ ⎜ 2⎟ ⎟
⎜ ⎝ x ⎠ ⎟
lim ⎜────────────────⎟
x─→0⁻⎜ 4 ⎟
⎝ x ⎠
0
⎛ -1 ⎞
⎜ ───⎟
3⎜ 2⎟
d ⎜ x ⎟
───⎝ℯ ⎠
3
dx
-1
───
2
⎛ 9 2 ⎞ x
4⋅⎜6 - ── + ──⎟⋅ℯ
⎜ 2 4⎟
⎝ x x ⎠
────────────────────
5
x
⎛ -1 ⎞
⎜ ───⎟
⎜ 2⎟
⎜ ⎛ 9 2 ⎞ x ⎟
⎜4⋅⎜6 - ── + ──⎟⋅ℯ ⎟
⎜ ⎜ 2 4⎟ ⎟
⎜ ⎝ x x ⎠ ⎟
lim ⎜────────────────────⎟
x─→0⁺⎜ 5 ⎟
⎝ x ⎠
0
⎛ -1 ⎞
⎜ ───⎟
⎜ 2⎟
⎜ ⎛ 9 2 ⎞ x ⎟
⎜4⋅⎜6 - ── + ──⎟⋅ℯ ⎟
⎜ ⎜ 2 4⎟ ⎟
⎜ ⎝ x x ⎠ ⎟
lim ⎜────────────────────⎟
x─→0⁻⎜ 5 ⎟
⎝ x ⎠
0
⎛ -1 ⎞
⎜ ───⎟
4⎜ 2⎟
d ⎜ x ⎟
───⎝ℯ ⎠
4
dx
-1
───
2
⎛ 75 36 4 ⎞ x
4⋅⎜-30 + ── - ── + ──⎟⋅ℯ
⎜ 2 4 6⎟
⎝ x x x ⎠
───────────────────────────
6
x
⎛ -1 ⎞
⎜ ───⎟
⎜ 2⎟
⎜ ⎛ 75 36 4 ⎞ x ⎟
⎜4⋅⎜-30 + ── - ── + ──⎟⋅ℯ ⎟
⎜ ⎜ 2 4 6⎟ ⎟
⎜ ⎝ x x x ⎠ ⎟
lim ⎜───────────────────────────⎟
x─→0⁺⎜ 6 ⎟
⎝ x ⎠
0
⎛ -1 ⎞
⎜ ───⎟
⎜ 2⎟
⎜ ⎛ 75 36 4 ⎞ x ⎟
⎜4⋅⎜-30 + ── - ── + ──⎟⋅ℯ ⎟
⎜ ⎜ 2 4 6⎟ ⎟
⎜ ⎝ x x x ⎠ ⎟
lim ⎜───────────────────────────⎟
x─→0⁻⎜ 6 ⎟
⎝ x ⎠
0
$
HTML5
<div id="graph0"></div> <pre id="output0"></pre> <label for="r0">r = </label> <input id="r0" type="number" min="0" value="0.5"> <label for="dx">dx = </label> <input id="dx" type="number" min="0" step="0.001" value="0.0001"> <br> <label for="x1">x1 = </label> <input id="x1" type="number" value="-1.5"> <label for="x2">x2 = </label> <input id="x2" type="number" value="1.5"> <br> <label for="y1">y1 = </label> <input id="y1" type="number" value="-1.5"> <label for="y2">y2 = </label> <input id="y2" type="number" value="1.5"> <button id="draw0">draw</button> <button id="clear0">clear</button> <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/d3/4.2.6/d3.min.js" integrity="sha256-5idA201uSwHAROtCops7codXJ0vja+6wbBrZdQ6ETQc=" crossorigin="anonymous"></script> <script src="sample14.js"></script>
JavaScript
let div0 = document.querySelector('#graph0'),
pre0 = document.querySelector('#output0'),
width = 600,
height = 600,
padding = 50,
btn0 = document.querySelector('#draw0'),
btn1 = document.querySelector('#clear0'),
input_r = document.querySelector('#r0'),
input_dx = document.querySelector('#dx'),
input_x1 = document.querySelector('#x1'),
input_x2 = document.querySelector('#x2'),
input_y1 = document.querySelector('#y1'),
input_y2 = document.querySelector('#y2'),
inputs = [input_r, input_dx, input_x1, input_x2, input_y1, input_y2],
p = (x) => pre0.textContent += x + '\n',
range = (start, end, step=1) => {
let res = [];
for (let i = start; i < end; i += step) {
res.push(i);
}
return res;
};
let f1 = (x) => 2 * Math.exp(-1 / x ** 2) / x ** 3,
f2 = (x) => 2 * Math.exp(-1 / x ** 2) * (2 - 3 * x ** 2) / x ** 6,
f3 = (x) => 4 * (6 - 9 / x ** 2 + 2 / x ** 4) * Math.exp(-1 / x ** 2) / x ** 5;
let draw = () => {
pre0.textContent = '';
let r = parseFloat(input_r.value),
dx = parseFloat(input_dx.value),
x1 = parseFloat(input_x1.value),
x2 = parseFloat(input_x2.value),
y1 = parseFloat(input_y1.value),
y2 = parseFloat(input_y2.value);
if (r === 0 || dx === 0 || x1 > x2 || y1 > y2) {
return;
}
let points = [],
lines = [],
fns = [[f1, 'red'],
[f2, 'green'],
[f3, 'blue']],
fns1 = [],
fns2 = [];
fns
.forEach((o) => {
let [f, color] = o;
for (let x = x1; x <= x2; x += dx) {
let y = f(x);
points.push([x, y, color]);
}
});
fns1
.forEach((o) => {
let [f, color] = o;
lines.push([x1, f(x1), x2, f(x2), color]);
});
fns2
.forEach((o) => {
let [f, color] = o;
for (let x = x1; x <= x2; x += dx0) {
let g = f(x);
lines.push([x1, g(x1), x2, g(x2), color]);
}
});
let xscale = d3.scaleLinear()
.domain([x1, x2])
.range([padding, width - padding]);
let yscale = d3.scaleLinear()
.domain([y1, y2])
.range([height - padding, padding]);
let xaxis = d3.axisBottom().scale(xscale);
let yaxis = d3.axisLeft().scale(yscale);
div0.innerHTML = '';
let svg = d3.select('#graph0')
.append('svg')
.attr('width', width)
.attr('height', height);
svg.selectAll('line')
.data([[x1, 0, x2, 0], [0, y1, 0, y2]].concat(lines))
.enter()
.append('line')
.attr('x1', (d) => xscale(d[0]))
.attr('y1', (d) => yscale(d[1]))
.attr('x2', (d) => xscale(d[2]))
.attr('y2', (d) => yscale(d[3]))
.attr('stroke', (d) => d[4] || 'black');
svg.selectAll('circle')
.data(points)
.enter()
.append('circle')
.attr('cx', (d) => xscale(d[0]))
.attr('cy', (d) => yscale(d[1]))
.attr('r', r)
.attr('fill', (d) => d[2] || 'green');
svg.append('g')
.attr('transform', `translate(0, ${height - padding})`)
.call(xaxis);
svg.append('g')
.attr('transform', `translate(${padding}, 0)`)
.call(yaxis);
[fns, fns1, fns2].forEach((fs) => p(fs.join('\n')));
};
inputs.forEach((input) => input.onchange = draw);
btn0.onclick = draw;
btn1.onclick = () => pre0.textContent = '';
draw();
0 コメント:
コメントを投稿