# calculus help please

posted by
**amy**
.

Consider the function f(x)=2x+9x^–1.?

For this function there are four important intervals: (-inf,–A], [A,B),(B,C), and [C,inf)

where A, and C are the critical numbers and the function is not defined at B.

Find A= ?????

and B= 0

and C =?????