Thank you very much Acer, that does do the job. Is it possible to specify constraints (if thats the word, I'll give it a shot) at the time you define your function so Maple will remember it through out your use of that function. E.g. it would automatically apply the constraint when you solve, draw graphs ect.? Just to emphasize what I am trying to say: f(x) := x^2 , x > 0 Thanks again, Wuhtzu

Sorry my original post got messed up because some tags got passed wrong by the form. - - - - - - - - - - Hey Is it possible to specify a domain or boundaries for a function / expression and if so, how to do it? Here is an example of want I want to do: If I have the following function f(x)=x^2 and solve this problem solve(f(x)=4,x) I get the answers x=-2 or x=2, but I want to be able to specify that x has to be greater than 0 so Maple only returns the answer x=2. I used to work with a program called TI Interactive which comes with Texas Instruments' TI89 Calculator. In this program I could do this solve(f(x)=2,x)|x>0 but I can't in Maple. Generally I could use | to assign values and limitations to expressions. Can I do something similar in Maple? I apologize if I'm not expressing mathematics 100% correct / specific, but English isn't my first language and I takes time getting used speaking mathematics in english. Best regards Wuhtzu