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bobbym
2012-10-23 20:12:41

Series are of different types. For small values of x we use Taylor series. For large values we use Asymptotic expansions and Series that are expanded around infinity.

1) You could try to evaluate the integral using Romberg or Gaussian integration.

2) You truncate the various series expansions producing smaller approximations.

3) You look up the values in tables.

I have used the second one to come up with an example:

When x>=500.

http://numbers.computation.free.fr/Cons … rimes.html

now you will understand why there are only approximate answers.

Mint
2012-10-23 20:07:52

I just want to know how to find li(x),but you could show an example of your own.

bobbym
2012-10-23 19:31:47

Yes, but first I need that information from you.

1) Li(x), how big is x?

2)How many digits do you require because the answer is going to be in floating point.

Mint
2012-10-23 19:28:15

Could you show me some

bobbym
2012-10-23 19:20:45

Depends on the arguments or how much accuracy you need. There are several ways for each.

Mint
2012-10-23 19:10:39

That series is a little complex,isn't there a easier way?

anonimnystefy
2012-10-23 05:55:38
bobbym
2012-10-23 02:40:17

Hi Mint;

Welcome to the forum.

scientia
2012-10-23 02:08:45

Mint
2012-10-23 01:21:33

What is li(x)?I know it is logarithmic integral function,but how do i find li(x),for instance,what will be li(5)?