Alright, I understand clearly what a integral with no limits is, what it does, etc. It is simply backwards differentation (differentation deals with the instanteous slope of a parabola) And has no limit (no a to b), thus there must be a constant of integration since two (or more) of the same functions can look the same. It looks like: [tex]\int[/tex] I understand that these integrals are backwards differentation, thus backwards slopes? This doesn't make any sense, what exactly is their use then? I see alot of integrals without limits (They do not deal with area like the other type of integrals) being written down about the paradoxes of space (like on the discovery channel/science channel) This makes me even more interested on their use of them! Because I am hopefully going to be a professor in astrophysics! So far I'm 16, and I have a great start! I even tutor kids after school in math, its great. I understand the use of integrals with limits , from a to b like used in area, it makes sense! However I don't see the use of integrals without limits (thus with the C constant!) Help?