I should state that I am a Mathematica beginner but I checked the questions about machine vs arbitrary precision (such as: this one ) and I continue to have the following issue while trying to evaluate an expression:
After various calculations which include square roots and integrals, I arrive at a function foo[x_] which I want it to return a number.
On the contrary, it returns a numerical expression as shown below, together with the return values of different tests I made.

My end goal is to use foo to calculate other expressions, as well as to Plot this it, which I cannot do at the moment.
Any suggestions? Thanks in advance!


foo, which you do not provide... – Oleksandr R. Sep 23 '15 at 12:11fooin formatted form so people can Copy&Paste it and test by themselves and try to reproduce your problem. Help us to help you, as it is, we can hardly do anything for you. – rhermans Sep 23 '15 at 12:30FullFormto some of your inputs and results. – Sjoerd C. de Vries Sep 23 '15 at 13:06