# 3 maths problems

FischerRandom
Posers and Puzzles 03 Jan '07 03:43
1. 03 Jan '07 03:432 edits
1.Differentiate sin inverse (x+1/x) with respect to x.
2.what is the answer of the series
(a-x)(b-x)(c-x)..............(z-x).
3.integral of e to the power of x square dx.
solve them and post the solution.
2. 03 Jan '07 06:04
I gave that up seven years ago, sorry.
3. XanthosNZ
Cancerous Bus Crash
03 Jan '07 08:17
1. (1-1/x^2)/(1-(x+1/x)^2)^(1/2)

2. 0

3. Doesn't exist
4. 03 Jan '07 09:06
Originally posted by XanthosNZ
1. (1-1/x^2)/(1-(x+1/x)^2)^(1/2)

2. 0

3. Doesn't exist
second and third are right but not the first.keep trying.
5. XanthosNZ
Cancerous Bus Crash
03 Jan '07 10:05
Originally posted by FischerRandom
second and third are right but not the first.keep trying.
Oh really? Because that's what maple gives me for the differential of arcsin(x+1/x) wrt x.
Perhaps you meant arcsin((x+1)/x) or sin (x+1/x)^-1 or something else entirely.

Keep trying.

PS. These questions are stupid.
6. 03 Jan '07 13:31
Sorry - it's been a while since I did maths. Why doesn't the third exist?

I am reading it as S (e^(x^2)) dx, maybe I'm wrong there? I can't see why that has no integral solution.
7. XanthosNZ
Cancerous Bus Crash
03 Jan '07 13:45
Originally posted by Zeddicus
Sorry - it's been a while since I did maths. Why doesn't the third exist?

I am reading it as S (e^(x^2)) dx, maybe I'm wrong there? I can't see why that has no integral solution.
Try it.
8. 03 Jan '07 13:51
Originally posted by XanthosNZ
Oh really? Because that's what maple gives me for the differential of arcsin(x+1/x) wrt x.
Perhaps you meant arcsin((x+1)/x) or sin (x+1/x)^-1 or something else entirely.

Keep trying.

PS. These questions are stupid.
Using maple? Well, then it is not hard... ðŸ™„
Using Fritz too? ðŸ˜‰
9. 03 Jan '07 14:00
Lol, there's no way I can do it, but I don't take my inability to do something as proof that something can't be done! That would make mathematics far too easy.

Is there a consise proof that it's not possible?
10. XanthosNZ
Cancerous Bus Crash
03 Jan '07 14:03
Originally posted by FabianFnas
Using maple? Well, then it is not hard... ðŸ™„
Using Fritz too? ðŸ˜‰
If you don't want to use maple (or similar) you basically go to a big table of differentials and look it up.
It's the same in the end and one is faster than the other.

I'll assume that the last comment is a joke.
11. 03 Jan '07 15:42
Originally posted by XanthosNZ
Oh really? Because that's what maple gives me for the differential of arcsin(x+1/x) wrt x.
Perhaps you meant arcsin((x+1)/x) or sin (x+1/x)^-1 or something else entirely.

Keep trying.

PS. These questions are stupid.
no i mean only sin inverse and nothing else.
12. 03 Jan '07 17:09
Originally posted by XanthosNZ
If you don't want to use maple (or similar) you basically go to a big table of differentials and look it up.
It's the same in the end and one is faster than the other.

I'll assume that the last comment is a joke.
Of course it was a joke, hence the blinking MrSmilie.
But still, solving a mathematical puzzle using Maple doesn't give any credits, as solving a mate-in-two using Fritz...
I don't think the threadmaker, the puzzlemaker, ment that the puzzle would be solved with silicon intelligence but with the more sofisticated computer, called brain.
Now, before you get angry I put another MrSmiley to smooth any hard feelings: ðŸ˜µ
13. BigDoggProblem
03 Jan '07 17:38
Originally posted by FabianFnas
Of course it was a joke, hence the blinking MrSmilie.
But still, solving a mathematical puzzle using Maple doesn't give any credits, as solving a mate-in-two using Fritz...
I don't think the threadmaker, the puzzlemaker, ment that the puzzle would be solved with silicon intelligence but with the more sofisticated computer, called brain.
Now, before you get angry I put another MrSmiley to smooth any hard feelings: ðŸ˜µ
How about solving a mate in 100+ moves with 2 Knights versus a Pawn? There are some of those in the Nalimov tablebase. What human would want to bother solving such a tedious and lengthy endgame?

Puzzlemakers do not always intend for their puzzle to be solved by humans. See question 2 of the puzzle in .
14. 03 Jan '07 18:27
Originally posted by BigDoggProblem
How about solving a mate in 100+ moves with 2 Knights versus a Pawn? There are some of those in the Nalimov tablebase. What human would want to bother solving such a tedious and lengthy endgame?

Puzzlemakers do not always intend for their puzzle to be solved by humans. See question 2 of the puzzle in .
True, but how hard can it be to press a button on a keyboard? If I solved a mate-in-99 with Fritz, does people say "Oh, how clever you are"? I don't think so.

I know Xantoz is intelligent (no Smiley here) but even my nephew, 9 years old can press a button. Does this mean that he is clever as Xantoz? I don't think so.
15. 03 Jan '07 19:144 edits
Originally posted by FischerRandom
no i mean only sin inverse and nothing else.
If y = sin(x) then x = arcsin(y) or x = sin^-1(y)

saying sin inverse (y) isn't very clear as it can be confused with

x = 1 / sin(y) or x = sin(y)^1

EDIT:

1. The derivative of f(x) = arcsin x is given by

f '(x) = 1 / sqrt(1 - x^2)