二倍角公式 - 百度百科
WEB二倍角公式是数学三角函数中常用的一组公式，通过角α的三角函数值的一些变换关系来表示其二倍角2α的三角函数值，二倍角公式包括正弦二倍角公式、余弦二倍角公式以及正切二倍角公式。在计算中可以用来化简计算式、减少求三角函数的次数，在工程中也有广泛的运用。
y=2cos(x) - Desmos
WEBDesmos是一个免费的在线图形计算器，可以绘制y=2cos (x)的图像，并进行各种变换和分析。你还可以探索其他函数、方程式、统计、微积分等数学主题，并使用滑块和动画图表等功能。
y=2cos(x) - Desmos
WEBExplore math with our beautiful, free online graphing calculator. Graph functions, plot points, visualize algebraic equations, add sliders, animate graphs, and more.
Trigonometric Identities - Math.com
WEBLearn the definitions and formulas of trigonometric functions and their identities. Find sin (2x) and cos (2x) in the list of common angles and the law of cosines.
2cos (x) - Wolfram|Alpha
WEBEnter 2cos (x) in the natural language or math input box and get the plots, roots, approximate forms, properties, and step-by-step solutions of the function. Wolfram|Alpha is a powerful computational knowledge engine that covers various domains and topics.
2cosx - Symbolab
WEBEnter 2cosx and get the solution, graph, and explanation of the trigonometric function. Symbolab is a free online tool for math problems from Pre Algebra to Calculus.
求解 y=2cosx | Microsoft Math Solver
WEBhttps://socratic.org/questions/how-do-you-find-the-intersections-points-of-y-2cosx-and-y-3sin-3x Generate graphs of the functions and find their points of intersection. Explanation: As this question is in the "Graphing Trigonometric Functions" section, I assume that the graphical solution is ...
三角函数化简计算器 - Symbolab 数学求解器
WEB免费的三角函数化简计算器 - 一步步将三角函数表达式化至最简形式
三角函数公式归纳大全 - 哔哩哔哩
WEBJan 2, 2021 · 本文收集了三角函数的各种公式，包括诱导公式、两角公式、三角公式、半角公式、辅助角公式等，并给出了一些例题的解法。本文与查询“sinx-cosx”无直接关系，但可用公式推导出sinx-cosx的值域和性质。
Solve y=2cos(x) | Microsoft Math Solver
WEBFind the solutions of y=2cos(x) for x in terms of arccos(2y) and 2πn, where n is an integer. See the graph, quiz, videos and related concepts of trigonometry.