What are two things we look for in an equation that can tell us what's NOT in it's domain?

1. Value for which denominator is 0.

2. Value for which we get negative sing inside the root or log.

Step-by-step explanation:

Domain is the set of input values.

If a function is not defined for a set of value then they are NOT in it's domain.

Two we look for in an equation that can tell us what's NOT in it's domain :

1. Value for which denominator is 0.

2. Value for which radicand is negative because negative values inside the square roots are not real.  Value for which log values are negative because log is not defined for negative values.