“half‐angle formula”的概念、定义、翻译、参考文献-科学参考

单词	half‐angle formula
释义	half‐angle formula Mathematics Trigonometric formulae expressing a function of a half‐angle in terms of the full angle or expressing a function of an angle in terms of half‐angles. $\begin{array}{l} sin \frac{x}{2} = \pm \sqrt{\frac{1 - cos x}{2},} cos \frac{x}{2} = \pm \sqrt{\frac{1 + cos x}{2},} \\ and if t = tan \frac{x}{2}, sin x = \frac{2 t}{1 + t^{2}}, \\ cos x = \frac{1 - t^{2}}{1 + t^{2}}, tan x = \frac{2 t}{1 - t^{2}} . \end{array}$
随便看	Kamiokande Kammerer, Paul Kamp, Peter van de Kampuchea KAM theorem Kanagawa, Treaty of (31 March 1854)) Kanaka kandite Kanem-Bornu kangaroo Kangxi (1654–1722) Kang Youwei (1858–1927) Kanopus-V1 Kanopus-V-1K 1 Kanopus-Vulkan-Infra-Krasny-1 Kanopus-Vulkan N1 Kansan I and II Kansas–Nebraska Act (1854) Kant, Immanuel (1724–1804) Kant’s law kaolin kaolinite kaolinitization kaolinization kaon

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