作曲 : 石伟 | |
作词 : 石伟 | |
歌曲歌词请见《洛天依 - 三角函数歌诀》 | |
三角函数公式小结: | |
1、象限角三角函数正负 | |
一全正,二正弦,三正切,四余弦 | |
2、三角函数诱导公式 | |
(1)sin(a+2兀k)=sina | |
(cos,tan也相同,k属于Z) | |
(2)sin(兀+a)=-sina | |
cos(兀+a)=-cosa | |
tan(兀+a)=tana | |
(3)sin(-a)=-sina | |
cos(-a)=cosa | |
tan(-a)=-tana | |
(4)sin(兀-a)=sina | |
cos(兀-a)=-cosa | |
tan(兀-a)=-tana | |
(5)sin(兀/2-a)=cosa | |
cos(兀/2-a)=sina | |
tan(兀/2-a)=cota | |
(6)sin(兀/2+a)=cosa | |
cos(兀/2+a)=-sina | |
tan(兀/2+a)=-cota | |
奇变偶不变,符号看象限 | |
3、同三角函数基本关系公式 | |
(1)sin^2(a)+cos^2(a)=1 | |
(2)sina/cosa=tana | |
(3)sina=cosatana | |
(4)(sina+-cosa)^2=1+-2sinacosa | |
(5)tan^2(a)+1=1/(cosa^2) | |
(6)cota=1/tana | |
4、和角公式与差角公式 | |
(1)cos(a+b)=cosacosb-sinasinb | |
cos(a-b)=cosacosb+sinasinb | |
(2)sin(a+b)=sinacosb+cosasinb | |
sin(a-b)=sinacosb-cosasinb | |
(3)tan(a+b)=(tana+tanb)/(1-tanatanb) | |
tan(a-b)=(tana-tanb)/(1+tanatanb) | |
余余正正号相反, | |
正余余正号相同, | |
正切和除一积差。 | |
5、倍角公式与半角公式 | |
(1)二倍 | |
sin2a=2sinacosa | |
cos2a=cosa^2-sina^2 | |
=2cosa^2-1=1-2sina^2 | |
tana=2tana/(1-tana^2) | |
正倍二正余,余倍平方差, | |
切倍二正切,除一平方差。 | |
(2)三倍 | |
sin3a=3sina-4sina^2 | |
cos3a=4cosa^2-3cosa | |
tan3a=-tana^2tan(兀/2-a) | |
6、和差化积 | |
sina+sinb=2sin[(a+b)/2]cos[(a-b)/2] | |
cosa+cosb=2cos[(a+b)/2]cos[(a-b)/2] | |
sina-sinb=2cos[(a+b)/2]sin[(a-b)/2] | |
cosa-cosb=-2sin[(a+b)/2]sin[(a-b)/2] | |
7、积化和差 | |
sinacosb=[sin(a+b)+sin(a-b)]/2 | |
cosasinb=[sin(a+b)-sin(a-b)]/2 | |
cosacosb=[cos(a+b)+cos(a-b)]/2 | |
sinasinb=-[cos(a+b)-cos(a-b)]/2 | |
8、合一变形 | |
Asinwx+Bcoswx=(A^2+B^2)^-2sin(wx+c) | |
9、半角公式 | |
(sina/2)^2=(1-cosa)/2 | |
(cosa/2)^2=(1+cosa)/2 | |
(tana/2)^2=(1-cosa)/(1+cosa) | |
10、万能公式 | |
若tana/2=t | |
则sina=2t/(1+t^2) | |
cosa=(1-t^2)/(1+t^2) | |
tana=2t/(1-t^2) |
zuo qu : shi wei | |
zuo ci : shi wei | |
ge qu ge ci qing jian luo tian yi san jiao han shu ge jue | |
san jiao han shu gong shi xiao jie: | |
1 xiang xian jiao san jiao han shu zheng fu | |
yi quan zheng, er zheng xian, san zheng qie, si yu xian | |
2 san jiao han shu you dao gong shi | |
1 sin a 2 wu k sina | |
cos, tan ye xiang tong, k shu yu Z | |
2 sin wu a sina | |
cos wu a cosa | |
tan wu a tana | |
3 sin a sina | |
cos a cosa | |
tan a tana | |
4 sin wu a sina | |
cos wu a cosa | |
tan wu a tana | |
5 sin wu 2a cosa | |
cos wu 2a sina | |
tan wu 2a cota | |
6 sin wu 2 a cosa | |
cos wu 2 a sina | |
tan wu 2 a cota | |
qi bian ou bu bian, fu hao kan xiang xian | |
3 tong san jiao han shu ji ben guan xi gong shi | |
1 sin 2 a cos 2 a 1 | |
2 sina cosa tana | |
3 sina cosatana | |
4 sina cosa 2 1 2sinacosa | |
5 tan 2 a 1 1 cosa 2 | |
6 cota 1 tana | |
4 he jiao gong shi yu cha jiao gong shi | |
1 cos a b cosacosbsinasinb | |
cos ab cosacosb sinasinb | |
2 sin a b sinacosb cosasinb | |
sin ab sinacosbcosasinb | |
3 tan a b tana tanb 1tanatanb | |
tan ab tanatanb 1 tanatanb | |
yu yu zheng zheng hao xiang fan, | |
zheng yu yu zheng hao xiang tong, | |
zheng qie he chu yi ji cha. | |
5 bei jiao gong shi yu ban jiao gong shi | |
1 er bei | |
sin2a 2sinacosa | |
cos2a cosa 2sina 2 | |
2cosa 21 12sina 2 | |
tana 2tana 1tana 2 | |
zheng bei er zheng yu, yu bei ping fang cha, | |
qie bei er zheng qie, chu yi ping fang cha. | |
2 san bei | |
sin3a 3sina4sina 2 | |
cos3a 4cosa 23cosa | |
tan3a tana 2tan wu 2a | |
6 he cha hua ji | |
sina sinb 2sin a b 2 cos ab 2 | |
cosa cosb 2cos a b 2 cos ab 2 | |
sinasinb 2cos a b 2 sin ab 2 | |
cosacosb 2sin a b 2 sin ab 2 | |
7 ji hua he cha | |
sinacosb sin a b sin ab 2 | |
cosasinb sin a b sin ab 2 | |
cosacosb cos a b cos ab 2 | |
sinasinb cos a b cos ab 2 | |
8 he yi bian xing | |
Asinwx Bcoswx A 2 B 2 2sin wx c | |
9 ban jiao gong shi | |
sina 2 2 1cosa 2 | |
cosa 2 2 1 cosa 2 | |
tana 2 2 1cosa 1 cosa | |
10 wan neng gong shi | |
ruo tana 2 t | |
ze sina 2t 1 t 2 | |
cosa 1t 2 1 t 2 | |
tana 2t 1t 2 |
zuò qǔ : shí wěi | |
zuò cí : shí wěi | |
gē qǔ gē cí qǐng jiàn luò tiān yī sān jiǎo hán shù gē jué | |
sān jiǎo hán shù gōng shì xiǎo jié: | |
1 xiàng xiàn jiǎo sān jiǎo hán shù zhèng fù | |
yī quán zhèng, èr zhèng xián, sān zhèng qiē, sì yú xián | |
2 sān jiǎo hán shù yòu dǎo gōng shì | |
1 sin a 2 wù k sina | |
cos, tan yě xiāng tóng, k shǔ yú Z | |
2 sin wù a sina | |
cos wù a cosa | |
tan wù a tana | |
3 sin a sina | |
cos a cosa | |
tan a tana | |
4 sin wù a sina | |
cos wù a cosa | |
tan wù a tana | |
5 sin wù 2a cosa | |
cos wù 2a sina | |
tan wù 2a cota | |
6 sin wù 2 a cosa | |
cos wù 2 a sina | |
tan wù 2 a cota | |
qí biàn ǒu bù biàn, fú hào kàn xiàng xiàn | |
3 tóng sān jiǎo hán shù jī běn guān xì gōng shì | |
1 sin 2 a cos 2 a 1 | |
2 sina cosa tana | |
3 sina cosatana | |
4 sina cosa 2 1 2sinacosa | |
5 tan 2 a 1 1 cosa 2 | |
6 cota 1 tana | |
4 hé jiǎo gōng shì yǔ chà jiǎo gōng shì | |
1 cos a b cosacosbsinasinb | |
cos ab cosacosb sinasinb | |
2 sin a b sinacosb cosasinb | |
sin ab sinacosbcosasinb | |
3 tan a b tana tanb 1tanatanb | |
tan ab tanatanb 1 tanatanb | |
yú yú zhèng zhèng hào xiāng fǎn, | |
zhèng yú yú zhèng hào xiāng tóng, | |
zhèng qiē hé chú yī jī chà. | |
5 bèi jiǎo gōng shì yǔ bàn jiǎo gōng shì | |
1 èr bèi | |
sin2a 2sinacosa | |
cos2a cosa 2sina 2 | |
2cosa 21 12sina 2 | |
tana 2tana 1tana 2 | |
zhèng bèi èr zhèng yú, yú bèi píng fāng chà, | |
qiè bèi èr zhèng qiē, chú yī píng fāng chà. | |
2 sān bèi | |
sin3a 3sina4sina 2 | |
cos3a 4cosa 23cosa | |
tan3a tana 2tan wù 2a | |
6 hé chà huà jī | |
sina sinb 2sin a b 2 cos ab 2 | |
cosa cosb 2cos a b 2 cos ab 2 | |
sinasinb 2cos a b 2 sin ab 2 | |
cosacosb 2sin a b 2 sin ab 2 | |
7 jī huà hé chà | |
sinacosb sin a b sin ab 2 | |
cosasinb sin a b sin ab 2 | |
cosacosb cos a b cos ab 2 | |
sinasinb cos a b cos ab 2 | |
8 hé yī biàn xíng | |
Asinwx Bcoswx A 2 B 2 2sin wx c | |
9 bàn jiǎo gōng shì | |
sina 2 2 1cosa 2 | |
cosa 2 2 1 cosa 2 | |
tana 2 2 1cosa 1 cosa | |
10 wàn néng gōng shì | |
ruò tana 2 t | |
zé sina 2t 1 t 2 | |
cosa 1t 2 1 t 2 | |
tana 2t 1t 2 |