# Precalculus Examples

, ,
Set up the composite result function.
Evaluate by substituting in the value of into .
Remove parentheses.
Solve to find the values of that make the expression defined.
Set up the equation to solve for .
Subtract from both sides of the inequality.
For asymptotes and point discontinuity (denominator equals ), it is easier to find where the expression is undefined. These values are not part of the domain.
The domain is all values of that make the expression defined.