Here are a few options for a WordPress post tag description, targeting different levels of detail and target audience, all in Traditional Chinese:

**Option 1 (Concise & General):**

> 探討函數的相對極值，包括局部最大值和局部最小值。 理解如何識別和計算它們，以及它們的重要性。 (Tàn tǎo hán shù de xiāng duì jí zhí, bāo kuò jú bù zuì dà zhí hé jú bù zuì xiǎo zhí. Lǐ jiě rú hé shí bié hé jì suàn tā men, yǐ jí tā men de zhòng yào xìng.)
>
> *Translation: Exploring relative extreme values of functions, including local maxima and minima. Understanding how to identify and calculate them, and their importance.*

**Option 2 (Slightly More Detailed for Students):**

> 本文討論微積分中的「相對極值」，又稱為局部最大值和最小值。 我們將深入探討如何運用微積分工具，例如導數，來尋找函數的相對極值點，並了解這些極值在求解實際問題上的應用。 (Běn wén tǎo lùn wēi jī fēn zhōng de “xiāng duì jí zhí”, yòu chēng wèi jú bù zuì dà zhí hé zuì xiǎo zhí. Wǒ men jiāng shēn rù tàn tǎo rú hé yùn yòng wēi jī fēn gōng jù, lì rú dǎo shù, lái xún zhǎo hán shù de xiāng duì jí zhí diǎn, bìng liǎo jiě zhè xiē jí zhí zài qiú jiě shí jì wèn tí shàng de yīng yòng.)
>
> *Translation: This article discusses “relative extreme values” in calculus, also known as local maxima and minima. We will delve into how to use calculus tools, such as derivatives, to find relative extreme points of a function, and understand the application of these extreme values in solving practical problems.*

**Option 3 (Emphasis on Practical Applications):**

> 理解「相對極值」的概念，對優化、建模和解決實際問題至關重要。 探索如何利用數學方法找出函數的局部最高點和最低點，以及在現實生活中的應用，例如：工程設計、經濟分析等。 (Lǐ jiě “xiāng duì jí zhí” de gài niàn, duì yōu huà, jiàn mó hé jiě jué shí jì wèn tí zhì guān zhòng yào. Tàn suǒ rú hé lì yòng shù xué fāng fǎ zhǎo chū hán shù de jú bù zuì gāo diǎn hé zuì dī diǎn, yǐ jí zài xiàn shí shēng huó zhōng de yīng yòng, lì rú: gōng chéng shè jì, jīng jì fēn xī děng.)
>
> *Translation: Understanding the concept of “relative extreme values” is crucial for optimization, modeling, and solving real-world problems. Explore how to use mathematical methods to find the local highest and lowest points of a function, as well as applications in real life, such as: engineering design, economic analysis, etc.*

**Option 4 (Very Short and Informative):**

> 微積分中的相對極值： 局部最大值和最小值。 (Wēi jī fēn zhōng de xiāng duì jí zhí: jú bù zuì dà zhí hé zuì xiǎo zhí.)
>
> *Translation: Relative Extreme Values in Calculus: Local maxima and minima.*

**Which option to choose?**

* **Consider your target audience:** Are they calculus students, general learners, or professionals?
* **Think about the content linked to this tag:** If the related posts are technical, a more detailed description is appropriate. If the posts are for a general audience, a simpler explanation might be better.
* **Keyword relevance:** Ensure the description includes key terms like “相對極值” (xiang dui ji zhi), “局部最大值” (ju bu zui da zhi), and “局部最小值” (ju bu zui xiao zhi).

I recommend starting with **Option 2** or **Option 3** as they provide a good balance of information and conciseness for a WordPress tag. You can always adjust it later based on feedback.