Trigonometric Identities (thing)

SIN = Sine
COS = Cosine
TAN = Tangent
CSC = CoSecant
SEC = Secant
COT = CoTangent

#1
             
          1
SIN Θ = -----
        CSC Θ 

#2
          1
COS Θ = -----
        SEC Θ 

#3
        SIN Θ 
TAN Θ = -----
        COS Θ 

#4
        COS Θ     1 
COT Θ = ----- = -----
        SIN Θ   TAN Θ 

#5
          1
SEC Θ = -----
        COS Θ 

#6
           1
CSC Θ  = -----
         SIN Θ 

#7

SIN2 Θ + COS2 Θ = 1

#8

SEC2 Θ = 1 + TAN2 Θ 

#9

CSC2 Θ = 1 + COT2 Θ 

#10

SIN2 Θ = ½ ( 1 - COS 2Θ )

#11

COS2 Θ = ½ ( 1 + COS 2Θ )

#12

SEC2 Θ = 1 + TAN2 Θ

#13

CSC2 Θ = 1 + COT2 Θ

#14

SIN Θ COS Θ = ½ SIN 2Θ

#15

COS 2Θ = COS2 Θ - SIN2 Θ

#16
          2 TAN Θ
TAN 2Θ = ----------
         1 - TAN2 Θ