Derivative of Tangent Function

Theorem

 * $D_x \left({\tan x}\right) = \sec^2 x = \dfrac 1 {\cos^2 x}$

when $\cos x \ne 0$.

Also see

 * Derivative of Sine Function
 * Derivative of Cosine Function


 * Derivative of Cotangent Function


 * Derivative of Secant Function
 * Derivative of Cosecant Function