title: No "sqrtf" in math.h
body: <p>I am working under Ubuntu 11.04 and now engaged in a project whose source code uses routines like "sqrtf" or "lgamma", which are complained by my IDE, claiming that they cannot be found in "math.h". A senior member told me I need <strong>POSIX.1-2001</strong>. I used <code>ldd --version</code> to check my glibc's version and it gave <code>ldd (Ubuntu EGLIBC 2.13-0ubuntu13) 2.13</code>. I guessed the embedded version of glibc is simplified so I decided to make it upgraded to the full glibc-2.14. But after some search in aptitude I found that I have to do a manual installation. Getting frustrated all the way, I realize maybe the God is warning me off the wrong path. So...can anyone give some hints for me? Thank you~</p>