Math notes

Half angle identities for cosine: cos 0/2

+or- square root 1+cos0/2

Half angle identities for tangent: tan0/2

+or- square root 1-cos0/1+cos0

Half angle identities for sine:sine 0/2

+or- square root 1-cos0/2

cos(-x)/sin(-x)

-cotx

sin^2x+cos^2x

1

Double angle identities Cosine: cos20

1-2*sin^2 0

Double angle identities Cosine: cos20

2*cos^2 0-1

Double angle ldentities Sine: sin20

2*sino*cos0

Double Angle identities Tanget: tan20

2*tan0/1-tan^20

cos(2A)=cos(A+A)

cosA*cosA-sinA*sinA

difference of angles for cosine:cos(A-B)

cosA*cosB+sinA*sinB

sum of angles for cosine: cos(A +B)

cosA*cosB-sinA*sinB

Double angle identities Cosine: cos20

cos^2 0-sin^20

1+cot^2x

csc^2x

sin 2A =Sin(A+A)

sin(2A)= 2*sinA*cosA

sun of angles for sine:sin(A+B)

sinA*cosB+cosA*sinB

difference of angles for sine: sin(a-b)

sinA*cosB-cosA*sinB

1-cos^2x

sin^2x

sun of angles for tangent:tan(a+b)

tanA+tanB/1-tanA*tanB

difference of angles for tangent: tan(A-B)

tanA-tanB/1+tanA*tanB

sec^2x-1

tan^2x