What are the restrictions, if any, on values for the variables in the following radical expressions?
When you have a sqrt()
Make sure the value inside of it is nonnegative.
sqrt(3) works since 3 is not negative
sqrt(2.5) works since 2.5 is nonnegative.
sqrt(0) works since 0 is nonnegative.
sqrt(-3) does not work since -3 is negative.