Trigonometry!

Reciprocal Identities

1/sin = csc
1/csc = sin

1/cos = sec
1/sec = cos

1/tan = cot
1/cot = tan

Even/Odd
Identities

sin(-x) = -sin x

cos(-x) = -cos x

tan(-x) = -tan x

csc(-x) = -csc x

sec(-x) = -sec x

cot(-x) = -cot x

Pythagorean
Identities

sin^2 + cos^2 = 1

1 + tan^2 = sec^2

1 + cot^2 = csc^2

Basic
Trigonometric Functions
(super important)

Sine

r

Abbreviated: SINUsed to determine the ratio of a side opposite of a given angle(O/H)Inverse: Arcsin or Sin^-1

Cosine

r

Abbbreviated- COSUsed to determine the ratio of a side adjacent to a given angle(A/H)Inverse: Arccos or Cos^-1

Tangent

r

Abbreviated- TANUsed to determine the ratio of a side opposite and a side adjacent of a given angle(O/A)Inverse: Arctan or Tan^-1

Cosecant

r

Abbreviated: CSCCosecant is the reciprocal of the sine function.(H/O)Inverse: Arccsc or csc^-1

Secant

r

Abbreviation: SECSecant is the reciprocal function of cosine.(H/A)Inverse: Arcsec or sec^-1

Cotantgent

r

Abbreviation: COTCotangent is the reciprocal function of tangent.

Quotient
Identities

tan = sin/cos

cot = cos/sin

SOH-CAH-TOA