Tangent of Conjugate Angle

Theorem

 * $\map \tan {2 \pi - \theta} = -\tan \theta$

where $\tan$ denotes tangent.

That is, the tangent of an angle is the negative of its conjugate.

Also see

 * Sine of Conjugate Angle
 * Cosine of Conjugate Angle
 * Cotangent of Conjugate Angle
 * Secant of Conjugate Angle
 * Cosecant of Conjugate Angle