# Only real numbers (Fullsimplify) [duplicate]

I've to do some complex calculation with Mathematica and if I put in my code it gives me something big back, so is it possible to say that my variables are strictly real numbers, by sing the FullSimplify option?

My code:

FullSimplify[Abs[(230)*((230)/(((((r)*(I*100*Pi*l))/((r)+(I*100*Pi*l)))*((s+t+(I*100*Pi*m)+(I*100*Pi*n))))/((((r)*(I*100*Pi*l))/((r)+(I*100*Pi*l)))+((s+t+(I*100*Pi*m)+(I*100*Pi*n))))))]]


And all my variables are real and bigger than zero (r,s,l,t,m,n)! How can I that fit in in my code to make the outcome more likeable, an option that makes my code as small as possible?

• FullSimplify would be a start and reset variable/define variable
– user9660
Commented Sep 27, 2015 at 8:37
• I've edited my last part, thanks for your comment Commented Sep 27, 2015 at 8:48
• Fullsimplify is not FullSimplify
– user9660
Commented Sep 27, 2015 at 8:49
• Oh I didn't know that Commented Sep 27, 2015 at 9:14
• ComplexExpand. 15char Commented Sep 27, 2015 at 12:32

By reading the documentation you see that FullSimplify allows Assumptions, similar to Assuming which could also help using ComplexExpand
FullSimplify[