Domain Functions 1224E0
1. Let's start by stating the problem: We want to understand how to find the domain of a function.
2. The domain of a function is the set of all possible input values ($x$) for which the function is defined.
3. Important rules to consider when finding domains:
- The function cannot have division by zero.
- The function cannot have a negative number inside an even root (like square root).
- The function must have real values (no complex numbers unless specified).
4. Step-by-step method:
- Identify any denominators and set them not equal to zero.
- Identify any even roots and set the radicand (expression inside the root) greater than or equal to zero.
- Solve these inequalities or equations to find the allowed values of $x$.
5. Example: Find the domain of $f(x) = \frac{1}{\sqrt{x-3}}$.
- The denominator $\sqrt{x-3}$ cannot be zero or negative.
- So, $x-3 > 0$.
- Solve: $x > 3$.
- Therefore, the domain is all real numbers greater than 3.
6. Summary: To find the domain, look for restrictions like division by zero or even roots of negative numbers, then solve inequalities to find valid $x$ values.
This method works for most functions you will encounter.