Domain of a Function is a Set of Values under which the Function is defined or a Set of Values which satisfy the respective Function.
The Given Function is : f(x) = [tex]\frac{3}{x + 5}[/tex]
When function is a Fraction, it Cannot be defined when the denominator becomes zero. Because when the denominator is zero, the fraction tends to ∞ (because anything divided by zero tends to ∞)
As the given function is a Fraction which contains the variable x in it. The given Function is not defined when x + 5 = 0
⇒ The Given Function is not Defined when x = -5
Because at x = -5, The Function tends to ∞ and becomes undefinable
So, As the Domain is the set of Values which satisfies the Function, -5 cannot be the part of the Domain
-5 is the Number which is not part of the Domain
