sin(π-a)=sina
cos(π-a)=-cosa
tan(π-a)=-tana
theseareallthose"namedonotchange"
Aspigoestohalfpithedifferenceshallbehuge
sin(π2+a)=cosa
sin(π2-a)=cosa
cos(π2+a)=-sina
cos(π2-a)=sina
tan(π2+a)=-cota
tan(π2-a)=cota
thatistosaytheoddswillchange,evensareconserved
thenotationsthattheygetdependonwheretheyare
butnomatterwhereyouare
Ivegottasaythat
Ifyouweremysinecurve,Idbeyourcosinecurve
Illbeyourderivative,youllbemynegativeone
Asyouchangeyouamplitude,Ichangemyphase
wecanoscillatefreelyintheexternalspace
Aswechangeourperiodandcostantathand
wetravelfromtheorigintoinfinity
Itsyousine,andyoucosine
whomakecharmingmusicaroundtheworld
Itsyoutangent,cotangent
whoproclaimthetruemeaningofcentrosymmetry
Nobbox
南娇娇:还有一段啊,大家忍耐一下。
Youwannameasurewidthofariver,heightofatower
Youscratchyourheadwhichcostyoumorethananhour
Youdontneedtoaskany"gods"or"master"forhelp
thisgroupofformulasaregonnahelpyousolve
sin(a+β)=sina?cosβ+cosa?sinβ
cos(a+β)=cosa?cosβ-sina?sinβ
tan(a+β)=(tana+tanβ)(1-tana?tanβ)
sin(a-β)=sina?cosβ-cosa?sinβ
cos(a-β)=cosa?cosβ+sina?sinβ