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  • 常规

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  • 导言:单位圆圈和三角函数

    Many researchers model data that has a cyclical and repeating nature by using trigonometric functions. For instance, Stuart Kenny, an early scientist, coined the term "sinusoidal" while observing the growth and harvest of soybeans. He noticed that since the growth and harvest pattern was directly connected to the time of the year, the plant maturity reached the same level every few months. That made its maturity level periodic, with a period length of 60 days.
    ::许多使用三角函数具有周期性和重复性的研究人员模型数据。 比如,早期科学家斯图尔特·肯尼(Stuart Kenny)在观察大豆生长和收成的同时创造了“类固醇”一词。 他注意到,由于生长和收成模式与当年时间直接相关,植物成熟度每几个月就达到同样的水平。 这使得其成熟度定期达到60天。

    lesson content

    Other researchers have noticed the same repetitive nature with ocean tides and seasonal temperature. Even the height of a person on a Ferris wheel can be modeled through the use of sine and cosine functions. In this chapter, we will study characteristics of the six basic trigonometric functions, such as how these periodic functions all repeat their pattern over time. As with all function families, the characteristics will be established and applied to real-world examples.
    ::其他研究人员也注意到与海潮和季节性温度相同的重复性。 即使是Ferris轮上的一个人的高度也可以通过使用正弦和余弦函数来模拟。 在本章中,我们将研究六种基本三角函数的特性,例如这些周期性函数如何随着时间的流逝而重复。 和所有功能性家庭一样,这些特性将被确定并应用到现实世界的例子中。