The set theoretic definition of function
known to us presently is simply an abstraction of the definition given by Dirichlet
in a rigorous manner Rationalised 2023-24
 18
MATHEMATICS
vMathematics, in general, is fundamentally the science of
self-evident things — FELIX KLEIN v
2 1  Introduction
In Chapter 1, we have studied that the inverse of a function
f, denoted by f –1, exists if f is one-one and onto