Consider the function f ( x ) = x 4 ? 2 x 2 ? 3 . Answer each of the following questions:

1. What is the domain of f ( x )? Use interval notation.
2. What are the critical values (x-coordinates) of f, if they exist?
3. For what intervals of x is the function increasing/decreasing? Use interval notation.
4. Find and categorize all extrema and identify the x-values at which they occur.
5. Does f have any inflection points? If so, state their ( x , y ) coordinates.
6. Determine where f ( x ) is concave up and concave down. Use interval notation.