# Integration limits doubt

1. Apr 5, 2014

### shawrix

I saw in a question related to Signals and systems that the limits were taken from 5- to 10+ where the signs were in the feet of the numbers..lol..i don't know what you call that. What does this mean?

2. Apr 5, 2014

### Simon Bridge

You mean like: $$y=\int_{5_-}^{10_+}f(x)dx$$ ?

Can you provide a reference or a context?

Last edited: Apr 5, 2014
3. Apr 5, 2014

### Staff: Mentor

This is not a precalc question. I am moving it to the General Math sections.

4. Apr 5, 2014

### Staff: Mentor

This would make more sense if the integral were written like this:

$$\int_{5^+}^{10^-}f(x)dx$$

That would indicate that there were discontinuities at 5 and 10. To evaluate such an integral, you need to break the integral into two integrals, and use limits at the problem points.

As stated in post #1, this doesn't make much sense to me.

5. Apr 5, 2014

### mathman

Unless there are delta functions at x = 5 or x = 10, the + or - subscripts on the limits have no effect.

6. Apr 5, 2014

### Staff: Mentor

Before we postulate further on what the question is asking, we should wait for the OP to return to clarify the question.