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