Trig Identities

cotX = 1 ÷ tanX

secX = 1 ÷ cosX

cosecX = 1 ÷ sinX

tanX = sinX ÷ cosX

ccos²X + sin²X = 1

cotX = cosX ÷ sinX

cot²X + 1 = cosec²X

1 + tan²X = sec²X

sin(A+B) = sinAcosB + cosAsin

sin(A-B) = sinAcosB - cosAsinB

cos(A+B) = cosAcosB - sinAsinB

cos(A-B) = cosAcosB + sinAsinB

tan(A+B) = (tanA+tanB) ÷ (1 - tanAtanB)

tan(A-B) = (tanA-tanB) ÷ (1 + tanAtanB)

sin(2A) = 2sinAcosA

cos(2A) = cos²A - sin²A

tan(2A) = 2tanA ÷ 1-tan²A