Define each of the following:
`"(i) injective function "" ""(ii) surjective function "`
`"(iii) bijective function "" ""(iv) many -one function"`
`"(v) into function "" "`
`Give an example of each type of functions.

Explanation

### Step-by-Step Text Solution

**(i) Injective Function:**
An injective function (also known as a one-to-one function) is defined as follows:
A function \( f: A \to B \) is said to be injective if for every pair of elements \( x_1, x_2 \in A \), whenever \( f(x_1) = f(x_2) \), it must follow that \( x_1 = x_2 \). In other words, different elements in the domain \( A \) map to different elements in the codomain \( B \).

**Example:**
Let \( f(x) = x + 9 \) where \( A \) is the set of real numbers.
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