谁知道三角函数公式··好久没碰到这个东东了···现在有事要用到···最好能说的简单易懂····
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![谁知道三角函数公式··好久没碰到这个东东了···现在有事要用到···最好能说的简单易懂····](/uploads/image/z/6909117-69-7.jpg?t=%E8%B0%81%E7%9F%A5%E9%81%93%E4%B8%89%E8%A7%92%E5%87%BD%E6%95%B0%E5%85%AC%E5%BC%8F%C2%B7%C2%B7%E5%A5%BD%E4%B9%85%E6%B2%A1%E7%A2%B0%E5%88%B0%E8%BF%99%E4%B8%AA%E4%B8%9C%E4%B8%9C%E4%BA%86%C2%B7%C2%B7%C2%B7%E7%8E%B0%E5%9C%A8%E6%9C%89%E4%BA%8B%E8%A6%81%E7%94%A8%E5%88%B0%C2%B7%C2%B7%C2%B7%E6%9C%80%E5%A5%BD%E8%83%BD%E8%AF%B4%E7%9A%84%E7%AE%80%E5%8D%95%E6%98%93%E6%87%82%C2%B7%C2%B7%C2%B7%C2%B7)
谁知道三角函数公式··好久没碰到这个东东了···现在有事要用到···最好能说的简单易懂····
谁知道三角函数公式··
好久没碰到这个东东了···现在有事要用到···最好能说的简单易懂····
谁知道三角函数公式··好久没碰到这个东东了···现在有事要用到···最好能说的简单易懂····
1.诱导公式
sin(-a) = - sin(a)
cos(-a) = cos(a)
sin(π/2 - a) = cos(a)
cos(π/2 - a) = sin(a)
sin(π/2 + a) = cos(a)
cos(π/2 + a) = - sin(a)
sin(π - a) = sin(a)
cos(π - a) = - cos(a)
sin(π + a) = - sin(a)
cos(π + a) = - cos(a)
2.两角和与差的三角函数
sin(a + b) = sin(a)cos(b) + cos(α)sin(b)
cos(a + b) = cos(a)cos(b) - sin(a)sin(b)
sin(a - b) = sin(a)cos(b) - cos(a)sin(b)
cos(a - b) = cos(a)cos(b) + sin(a)sin(b)
tan(a + b) = [tan(a) + tan(b)] / [1 - tan(a)tan(b)]
tan(a - b) = [tan(a) - tan(b)] / [1 + tan(a)tan(b)]
3.和差化积公式
sin(a) + sin(b) = 2sin[(a + b)/2]cos[(a - b)/2]
sin(a) sin(b) = 2cos[(a + b)/2]sin[(a - b)/2]
cos(a) + cos(b) = 2cos[(a + b)/2]cos[(a - b)/2]
cos(a) - cos(b) = - 2sin[(a + b)/2]sin[(a - b)/2]
4.积化和差公式
sin(a)sin(b) = - 1/2[cos(a + b) - cos(a - b)]
cos(a)cos(b) = 1/2[cos(a + b) + cos(a -b)]
sin(a)cos(b) = 1/2[sin(a + b) + sin(a - b)]
5.二倍角公式
sin(2a) = 2sin(a)cos(b)
cos(2a) = cos2(a) - sin2(a) = 2cos2(a) -1=1 - 2sin2(a)
6.半角公式
sin2(a/2) = [1 - cos(a)] / 2
cos2(a/2) = [1 + cos(a)] / 2
tan(a/2) = [1 - cos(a)] /sin(a) = sina / [1 + cos(a)]
7.万能公式
sin(a) = 2tan(a/2) / [1+tan2(a/2)]
cos(a) = [1-tan2(a/2)] / [1+tan2(a/2)]
tan(a) = 2tan(a/2) / [1-tan2(a/2)]
三角函数公式太多了,不知道你要用哪个啊?