All trignometric functions are periodic but only sine or cosine functions are used to define SHM. Why?

Explanation

A periodic function is one whose value repeats after a definite initerval. Since the value of all trignometric functions repeat with an initerval of 0 to `2pi rad`, hence, they all are periodic. The sine and cosine functions take values between `-1` to `+1` only. As a result of it, they can be used to represent a bounded motion like SHM. But the functions like tangent, colangent, secant and cosecant can take values between o to `oo` both positive and negative. Therefore, these functions are not able to represent bounded motion which is a requirement for SHM.