need calc write up help

[Trezza]

I have to do some basic integration but i have to do a write up on it. I have never done anything like this before so any help would be good. This is one of many problems. Your supposed to do the work and list the steps then compare the advantages/disadvantages of each.

Intergrate x /(x^2 + 25) dx first by ordinary substituion and then again by trig subs.

Any help would be appreciated, thanks!

 

[Trezza]

this is what i got so far.

Note that ~ will represent the intergral symbol.

1a.) The first intergral is [ ~ x /(x^2 + 25) dx ]. We are going to solve this problem by using the ordinary substitution and then compare that to the trigonometric substitution.

I) We substitute U for (x^2 +25) and du = 2x to get the following: 1/2 ~ 2x/(x^2 +25) dx. Now we have both our U and dU so we are ready to substitute. Replacing the x's with u's we get this: 1/2~ du/u. Integrate and the result is 1/2 LN | u | which when substituted becomes our answer: 1/2 ln | x^2 +25 |.

 

[vtqanh]

I solved the second part for you. Any part that you don't understand, take that as your exercises 😛

Click here

 

[nick1985]

dang, math is so hard. i dont understand a lick of that. its my biggest fear in college

 

[Lager]

Too much applied thinking in mathematiques.

 

[vtqanh]

Originally posted by: nick1985
dang, math is so hard. i dont understand a lick of that. its my biggest fear in college

if you took calculus, those shouldn't be that hard (those were just basic)

 

[Trezza]

Originally posted by: vtqanh

Originally posted by: nick1985
dang, math is so hard. i dont understand a lick of that. its my biggest fear in college

if you took calculus, those shouldn't be that hard (those were just basic)

thanks that helped me out alot. i am good at math but for some reason i can't get calculus at all. I took calc I 2 years ago and now finally taking calc2 so you can understand how some of the simple things might have been forgotten. Thanks for the in depth pic you posted on your website. it really helped to explain my answer. I wish more of the members on this forum were like you and the others that lended me aid in my calc delema.

-- Trezza