How can we help?

You can also find more resources in our Help Center.

15 terms

Trig Identities

STUDY
PLAY
odd IDs
sin(-x)=-sinx, csc(-x)=-cscx, tan(-x)=-tanx, cot(-x)=-cotx
even IDs
cos(-x)=cosx, sec(-x)=secx
Pythagorean IDs
sin²x+cos²x=1, tan²x+1=sec²x, 1+cot²x=csc²x
sin(A+B)=
sinAcosB+cosAsinB
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
sin2A=
2sinAcosA
cos2A=
cos²A-sin²A, 2cos²A-1, 1-2sin²A
tan2A=
2tanA/1-tan²A
sin(A/2)
±√1-cosA/2
cos(A/2)
±√1+cosA/2
tan(A/2)
±√1-cosA/1+cosA, 1-cosA/sin, sin/1+cosA