Question

if f(a) =b , then b is called image of a under f and a is called a______ of b​

Answer 1

Answer:

A function is said to be an into function from Set A to set B, if atleast one element of B is not connected to an element of A.

Here, when A is a proper subset of B, clearly, it will have lesser elements than set B, and those extra elements of set B will not be connected to any element of Set A. So it is an into function.