# Basic Propertiesof numbers

1. Aug 15, 2008

### Analysisfreak

1. The problem statement, all variables and given/known data
Find all number x for which 5-x^2 < 8

2. Relevant equations

3. The attempt at a solution
Adding -5 from both sides we get -x^2 < 3
x^2 > -3
then it is impossible that x > sqrt -3...
Any idea how to solve this step bystep

2. Aug 15, 2008

### epkid08

If you think about, you're asking when is five minus a positive number less than eight, and the answer to that is always, $$(-\infty, \infty)$$.

3. Aug 15, 2008

### HallsofIvy

Staff Emeritus
Not only is it possible for x2 to be greater than -3, since x2 is always non-negative it is always true!