Math Is Fun Forum

Ansh Agrawal

Member

Registered: 2012-01-26

Posts: 11

Integration - Some Problems. Please help.

Here are some problems I couldn't get through even though I may have done some of them many days back.. Could anyone please help in any of them?

1. Int of (e^x - 1)/(e^x + 1) dx
2. Int ( cox + xsinx ) / x ( x + cosx ) dx
3. Int 1 / x^2 * root of ( 1 - x^2 ) dx

4. Int of ( 1 + sinx ) / sinx ( 1- cosx ) dx

5. Int of 1 / root of ( x + ! ) + root of ( x - 1 ) dx

6. Int of ( 2x + 3 ) /( 3x - 4 ) dx

7. Int of 1/ ( 1 + e ^ x/2 ) dx

8. Int of root of ( x / a - x ) dx

9. Int of ( x - a )/ ( x + a ) dx

10. Int of ( x^2 + 1 ) / { ( x^2 - 1 ) ^ 2 } dx

11. Int of ( 2x - 5 ) * root of ( 2x + 1 ) dx

12. Int of ( x / a + bx ) dx

13. Int of 1 / x * root of ( x^2 - a^2 ) dx

14. Int of ( 2x^2 + 1 ) * sin ^ 2 ( 2x^3 + 3x ) dx

THANKS. 
Ansh Agrawal

anonimnystefy

Real Member

From: Harlan's World

Registered: 2011-05-23

Posts: 16,049

Re: Integration - Some Problems. Please help.

hi Ansh

1.try the substitution t=e^x+1

6.try the substitution t=3x-4

7.try the substitution t=1+e^(x/2)

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Ansh Agrawal

Member

Registered: 2012-01-26

Posts: 11

Re: Integration - Some Problems. Please help.

hi..thanks a lot could u tell me how do i enable the option of getting notified by email on replies like yours ?

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Integration - Some Problems. Please help.

Hi;

Subscribe to topic.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Ansh Agrawal

Member

Registered: 2012-01-26

Posts: 11

Re: Integration - Some Problems. Please help.

hey, thanks

Bob

Administrator

Registered: 2010-06-20

Posts: 10,163

Re: Integration - Some Problems. Please help.

hello again Ansh Agrawal

That's a very long list.  If you really want help with all of those ( as distinct from just letting someone else do your homework!) I suggest we look at them one at a time.  Help with one from the list may well enable you to do several others by yourself and you will learn more that way.

Looking at number 12, you have written

Int of ( x / a + bx ) dx

which means

which is pretty basic!

I suspect you meant

which is somewhat more tricky.

When posting a question, it is important to make it clear exactly what the question is.

Take care with where you put brackets.  Or better still, learn how to format a question using LaTex.

see http://www.mathisfunforum.com/viewtopic.php?id=4397 for how to do this.

Bob

Last edited by Bob (2012-02-14 20:20:27)

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Sometimes I deliberately make mistakes, just to test you!  …………….Bob