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		<id>https://tcs.nju.edu.cn/wiki/index.php?title=Mathematical_analysis&amp;diff=7496</id>
		<title>Mathematical analysis</title>
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		<updated>2016-01-15T23:27:55Z</updated>

		<summary type="html">&lt;p&gt;76.68.49.128: /* Differential calculus */ typo&lt;/p&gt;
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&lt;div&gt;&#039;&#039;&#039;Mathematical analysis&#039;&#039;&#039; is a part of [[mathematics]]. It is often shortened to &#039;&#039;&#039;analysis&#039;&#039;&#039;. It looks at [[Function (mathematics)|functions]], [[sequence]]s and [[series]]. These have useful properties and characteristics that can be used in [[engineering]]. The mathematical analysis is about [[continuous function]]s, [[differential calculus]] and [[Integral|integration]].&amp;lt;ref&amp;gt;{{Cite book|author=Hartmut Seeger|title=Mathematik|isbn=9 783833 107870|page=17|publisher=Tandem Verlag|location=Königswinter}}&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
[[Gottfried Wilhelm Leibniz]] and [[Isaac Newton]] developed most of the basis of mathematical analysis.&lt;br /&gt;
&lt;br /&gt;
== Parts of mathematical analysis ==&lt;br /&gt;
=== Limits ===&lt;br /&gt;
An example for mathematical analysis is [[Limit (mathematics)|limits]]. Limits are used to see what happens very close to things. Limits can also be used to see what happens when things get very big. For example, &amp;lt;math&amp;gt;\frac{1}{n}&amp;lt;/math&amp;gt; is never zero, but as n gets bigger &amp;lt;math&amp;gt;\frac{1}{n}&amp;lt;/math&amp;gt; gets close to zero. The limit of &amp;lt;math&amp;gt;\frac{1}{n}&amp;lt;/math&amp;gt; as n gets bigger is zero. It is usually said &amp;quot;The limit of &amp;lt;math&amp;gt;\frac{1}{n}&amp;lt;/math&amp;gt; as n goes to [[infinity]] is zero&amp;quot;. It is written as &amp;lt;math&amp;gt;\lim_{n\to\infty} \frac{1}{n}=0&amp;lt;/math&amp;gt;.&lt;br /&gt;
&lt;br /&gt;
The counterpart would be &amp;lt;math&amp;gt;{2} \times {n}&amp;lt;/math&amp;gt;. When the &amp;lt;math&amp;gt;{n}&amp;lt;/math&amp;gt; gets bigger, the limit goes to [[infinity]]. It is written as &amp;lt;math&amp;gt;\lim_{n\to\infty} {{2}} \times{n}=\infty&amp;lt;/math&amp;gt;.&lt;br /&gt;
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The [[fundamental theorem of algebra]] can be proven from some basic results in [[complex analysis]]. It says that every polynomial &amp;lt;math&amp;gt;f(x)&amp;lt;/math&amp;gt; with [[real]] or [[complex number|complex]] coefficients has a complex root. A root is a number &#039;&#039;x&#039;&#039; which gives a solution &amp;lt;math&amp;gt;f(x)=0&amp;lt;/math&amp;gt;. Some of these roots may be the same.&lt;br /&gt;
&lt;br /&gt;
=== Differential calculus ===&lt;br /&gt;
{{mainarticle|Differential calculus}}&lt;br /&gt;
The function &amp;lt;math&amp;gt;f(x) = {m}{x} + {c}&amp;lt;/math&amp;gt; is a [[line (geometry)|line]]. The &amp;lt;math&amp;gt;{m}&amp;lt;/math&amp;gt; shows the [[slope]] of the function and the &amp;lt;math&amp;gt;{c}&amp;lt;/math&amp;gt; shows the position of the function on the [[ordinate]]. With two points on the line, it is possible to calculate the slope &amp;lt;math&amp;gt;{m}&amp;lt;/math&amp;gt; with:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;math&amp;gt;m = \frac{y_1 - y_0}{x_1 - x_0}&amp;lt;/math&amp;gt;.&lt;br /&gt;
&lt;br /&gt;
A function of the form &amp;lt;math&amp;gt;f(x) = x^2&amp;lt;/math&amp;gt;, which is not linear, cannot be calculated like above. It is only possible to calculate the slope by using [[tangent]]s and [[secant line|secants]]. The secant passes through two points and when the two points get closer, it turns into a tangent.&lt;br /&gt;
&lt;br /&gt;
The new [[formula]] is &amp;lt;math&amp;gt;m = \frac{f(x_1) - f(x_0)}{x_1 - x_0}&amp;lt;/math&amp;gt;.&lt;br /&gt;
&lt;br /&gt;
This is called [[difference quotient]]. The &amp;lt;math&amp;gt;x_1&amp;lt;/math&amp;gt; gets now closer to &amp;lt;math&amp;gt;x_0&amp;lt;/math&amp;gt;. This can be expressed with the following formula:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;math&amp;gt;f&#039;(x) = \lim_{x\rightarrow x_0}\frac{f(x) - f(x_0)}{x - x_0}&amp;lt;/math&amp;gt;.&lt;br /&gt;
&lt;br /&gt;
The result is called [[derivative]] or slope of f at the point &amp;lt;math&amp;gt;{x}&amp;lt;/math&amp;gt;.&lt;br /&gt;
&lt;br /&gt;
=== Integration ===&lt;br /&gt;
{{mainarticle|Integration}}&lt;br /&gt;
The integration is about the calculation of [[area]]s.&lt;br /&gt;
&lt;br /&gt;
The symbol &amp;lt;math&amp;gt;\int_{a}^{b} f(x)\, \mathrm{d}x&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
is read as &amp;quot;the integral of f, from a to b&amp;quot; and refers to the area between the x-axis, the graph of function f, and the lines x=a and x=b. The &amp;lt;math&amp;gt;a&amp;lt;/math&amp;gt; is the point where the area should start and the &amp;lt;math&amp;gt;b&amp;lt;/math&amp;gt; where the area ends.&lt;br /&gt;
&lt;br /&gt;
== Other pages ==&lt;br /&gt;
Some topics in analysis are:&lt;br /&gt;
* [[Calculus]]&lt;br /&gt;
* [[Functional analysis]]&lt;br /&gt;
* [[Complex analysis]]&lt;br /&gt;
&lt;br /&gt;
Some useful ideas in analysis are:&lt;br /&gt;
* [[Series]]&lt;br /&gt;
* [[Sequence]]s&lt;br /&gt;
* [[Derivative]]s&lt;br /&gt;
* [[Integral]]s&lt;br /&gt;
&lt;br /&gt;
== References ==&lt;br /&gt;
{{reflist}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Calculus]]&lt;/div&gt;</summary>
		<author><name>76.68.49.128</name></author>
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