# *Even & odd functions

***Even & odd functions**

A function f (x) is called even, if f (- x) = + f (+x).

called, odd, if f (- x) = – f (+x).

otherwise called neither even nor odd.

cos and sec are even and remaining tan, cot, csc & sin are odd, thus

cos(- x) = + cos x & sec(- x) = + secx

sin(- x) = – sin x & csc(- x) = – csc x

tan(- x) = – tan x & cot(- x) = – cot x