Secant and Cosecant Functions

So far, we learned the basic functions of the trigonometry: sine, cosine, tangent, and cotangent functions. Conventionally, the reciprocals of sine and cosine functions are defined as two new functions. They are called cosecant and secant functions.

Secant of an angle A is the reverse of its cosine. Cosecant of the angle A is the reverse of its sine. The abbreviation for secant is "sec" and the abbreviation for cosecant is "csc." Thus,

Secant A = sec A =

Cosecant A = csc A =