A function for which every element of the range of the function corresponds to exactly one element

of the domain is known as one-to-one function.

If f(a) = f(b) => a = b, then the function f is known as one-to-one function.

Ex: Test whether g(x) = 5x - 3 is one-to-one?

Solu: Let g(a) = g(b)

=> 5a - 3 = 5b - 3

=> 5a = 5b - 3 + 3

=> 5a = 5b

=> a = b

So, the given function g(x) = 5x - 3 is one-to-one function.