韩玉《三角函数之歌》[MP3_LRC]

[00:00.00]90听音乐网 www.90T8.com  [00:06.43]When you first study math about 1234 [00:08.62]First study equation about xyzt [00:10.61]It will help you to think in a logical way [00:12.76]When you sing sine cosine cosine tangent [00:15.03]Sine cosine tangent cotangent [00:17.22]Sine cosine secant cosecant [00:19.30]Let's sing a song about trig-functions [00:21.48]Sin(2π+α)=sinα [00:23.70]Cos(2π+α)=cosα [00:25.92]Tan(2π+α)=tanα [00:27.69]Which is induction formula 1 and induction formula 2 [00:30.31]Sin(π+α)= -sinα [00:32.28]Cos(π+α)=-cosα [00:34.46]Tan(π+α)= tanα [00:36.66]Sin(π-α)= sinα [00:38.67]Cos(π-α)=-cosα [00:40.95]Tan(π-α)=-tanα [00:45.14]These are all those "name do not -change" [00:47.27]As pi goes to half pi the difference shall be huge [00:50.67]Sin(π/2+α)=cosα [00:53.43]Cos(π/2+α)=-sinα [00:57.71]Tan(π/2+α)=-cotα [01:02.13]Sin(π/2-α)=cosα [01:06.40]Cos(π/2-α)=sinα [01:10.24]Tan(π/2-α)=cotα [01:19.46]That is to say the odds will change evens are conserved [01:23.56]The notations that they get depend on where they are [01:27.66]But no matter where you are [01:30.08]I've gotta say that [01:32.32]If you were my sine curve I'd be your cosine curve [01:36.61]I'll be your derivative you'll be my negative one [01:40.60]As you change you amplitude I change my phase [01:44.79]We can oscillate freely in the external space [01:49.06]As we change our period and costant at hand [01:53.37]We travel from the origin to infinity [01:57.78]It's you sine and you cosine [02:01.87]Who make charming music around the world [02:06.09]It's you tangent cotangent [02:10.37]Who proclaim the true meaning of centrosymmetry [02:14.86]You wanna measure width of a river height of a tower [02:17.13]You scratch your head which cost you more than an hour [02:19.10]You don't need to ask any "gods" or" master" for help [02:21.42]This group of formulas are gonna help you solve [02:23.55]Sin(α+β)=sinα•cosβ+cosα•sinβ [02:28.10]Cos(α+β)=cosα•cosβ-sinα•sinβ [02:32.47]Tan(α+β)=(tanα+tanβ)/(1-tanα•tanβ) [02:41.33]Sin(α-β)=sinα•cosβ-cosα•sinβ [02:45.08]Cos(α-β)=cosα•cosβ+sinα•sinβ [02:49.16]Tan(α-β)=(tanα-tanβ)/(1+tanα•tanβ) [02:57.79]As you come across a right triangle you fell easy to solve [03:02.08]But an obtuse triangle gonna make you feel confused [03:05.89]Don't worry about what you do [03:08.00]There are always means to solve [03:10.42]As long as you master the sine cosine law [03:19.76]At this moment I've got nothing to say [03:23.60]As trig-functions rain down upon me [03:28.14]At this moment I've got nothing to say [03:31.93]Let's sing a song about trig-functions [03:36.39]Long live the trigonometric functions