Domain Math Example 2

Follow the full solution, then compare it with the other examples linked below.

Example 2

medium
Find the domain of g(x)=1x2โˆ’4g(x) = \frac{1}{x^2 - 4}.

Solution

  1. 1
    The denominator cannot be zero: x2โˆ’4โ‰ 0x^2 - 4 \neq 0.
  2. 2
    Factor: (xโˆ’2)(x+2)โ‰ 0(x - 2)(x + 2) \neq 0, so xโ‰ 2x \neq 2 and xโ‰ โˆ’2x \neq -2.
  3. 3
    The domain is all real numbers except ยฑ2\pm 2: (โˆ’โˆž,โˆ’2)โˆช(โˆ’2,2)โˆช(2,โˆž)(-\infty, -2) \cup (-2, 2) \cup (2, \infty).

Answer

(โˆ’โˆž,โˆ’2)โˆช(โˆ’2,2)โˆช(2,โˆž)(-\infty, -2) \cup (-2, 2) \cup (2, \infty)
For rational functions, exclude values that make the denominator zero. Factor the denominator to find these excluded values.

About Domain

The domain of a function is the complete set of allowable input values for which the function produces a defined, valid output.

Learn more about Domain โ†’

More Domain Examples