Hello,
your problem is that during project creation, you decided to use compiler settings/libraries with integral support only? So no float and doubles. You probably did this by mistake.
That's why your library in the project (ansibi.lib, the 'i' at the end of the name stand s for 'integral only') does not contain any floating point support, like 'extern double sqrt (double x)'.
You could now change the library, change the compiler options/etc, but this is more for an expert and if you know what you are doing. The easiest for you is probably run through the wizard again.
If you create a project with the project wizard, then around step 6 the wizard asks you if you want to use any floating point support: you need to select support for floating point (either IEEE32 or IEEE64).
PS: The reason for having an integral library is simply because of code density for several library functions: mainly printf(). If printf()/etc does not need to support the floating point formats, the code will be much more efficient and smaller.
Hope this helps.
Regards,
Erich