index: click on a letter A B C D E F G H I J K L M N O P Q R S T U V W X Y Z A to Z index index: subject areas numbers & symbols sets, logic, proofs geometry algebra trigonometry advanced algebra & pre-calculus calculus advanced topics probability & statistics real world applications multimedia entries

Cofunction Identities

Trig identities showing the relationship between sine and cosine, tangent and cotangent, and secant and cosecant. The value of a trig function of an angle equals the value of the cofunction of the complement of the angle.

 Cofunction Identities, radians Cofunction Identities, degrees sin (90° – x) = cos x cos (90° – x) = sin x tan (90° – x) = cot x cot (90° – x) = tan x sec (90° – x) = csc x csc (90° – x) = sec x