Tabla de identidades trigonométricas
1
𝑠𝑒𝑛2𝜃 + 𝑐𝑜𝑠2𝜃 = 1
2
𝑡𝑎𝑛2𝜃 + 1 = 𝑠𝑒𝑐2𝜃
3
𝑐𝑜𝑡2𝜃 + 1 = 𝑐𝑠𝑐2𝜃
4
𝑠𝑒𝑛(𝑎 + 𝑏)=𝑠𝑒𝑛 𝑎 cos 𝑏 + 𝑠𝑒𝑛 𝑏 cos𝑎
5
𝑠𝑒𝑛(𝑎 − 𝑏)=𝑠𝑒𝑛 𝑎 cos 𝑏 − 𝑠𝑒𝑛 𝑏 cos𝑎
6
𝑠𝑒𝑛 𝑎 cos 𝑏 = 1
2[𝑠𝑒𝑛(𝑎 + 𝑏)+𝑠𝑒𝑛(𝑎 − 𝑏)]
7
cos(𝑎 + 𝑏)= cos 𝑎 cos 𝑏 − 𝑠𝑒𝑛 𝑎 𝑠𝑒𝑛 𝑏
8
cos(𝑎 − 𝑏)= cos 𝑎 cos 𝑏 + 𝑠𝑒𝑛 𝑎 𝑠𝑒𝑛 𝑏
9
cos 𝑎 cos 𝑏 = 1
2[cos(𝑎 + 𝑏)+ cos(𝑎 − 𝑏)]
10
𝑠𝑒𝑛 𝑎 𝑠𝑒𝑛 𝑏 = 1
2[cos(𝑎 − 𝑏)− cos(𝑎 − 𝑏)]
11
𝑠𝑒𝑛(2𝜃)= 2 𝑠𝑒𝑛 𝜃 cos 𝜃
12
cos 2𝜃 = 𝑐𝑜𝑠2𝜃 − 𝑠𝑒𝑛2𝜃 = 2𝑐𝑜𝑠2𝜃 − 1 = 1 − 2𝑠𝑒𝑛2𝜃
13
𝑐𝑜𝑠2𝜃 = 1 + cos 𝜃
2 ; 𝑠𝑒𝑛2𝜃 = 1 − cos 𝜃
2
14
tan(𝑎 ± 𝑏)=tan 𝑎 ± tan 𝑏
1 ∓ tan 𝑎tan 𝑏