Question

I was wondering...

Answer 1

"will you marry me?" right?
XDD

Answer 2

lol

Answer 3

I'm writing it now, wait :D

Answer 4

haha okay

Answer 5

TYPE FASTER!!!!

Answer 6

lol

Answer 7

it gon be dramatic XD

Answer 8

I bet

Answer 9

OMFG

Answer 10

His computer froze :/

Answer 11

haha that would be funny xD

Answer 12

Usually
\[\int\limits \frac{ 1 }{ x } dx=\ln(x)+c\]
and
\[\int\limits x^{n}dx=\frac{ x^{n+1} }{ n+1 }\]

Then why do you get this
http://www.wolframalpha.com/input/?i=integral+x%2Fsqrt%289x%5E2%2B1%29

instead of \[\frac{ 1 }{ 18 } \int\limits \frac{ 1 }{ \sqrt{9x^2+1} } d (9x^2+1)=\frac{ 1 }{ 18 } \ln(\sqrt{9x^2+1})+c\]

Answer 13

It really took you that long to write that?

Answer 14

It's just that openstudy doesn't use normal LaTeX operators so I can type it faster.

Answer 15

haha its okay. i wish i could help but this gurl is not that good in math

Answer 16

omg i cant do that lol

Answer 17

if you substitute sqrt(9x^2+1) as t then can you proceed?

Answer 18

@ankit042 I can solve that integral, I was just wondering why the thing that I get with one of the fomulas is not equal to the other.

Answer 19

As in? if you look closely in the wolfram alfa case you are having dx and here it is a function of x

Answer 20

Yeah, but it's basically the same, look at \[\frac{ 1 }{ 18 } \int\limits \frac{ 1 }{ \sqrt{9x^2+1} } d (9x^2+1) \]
and apply the two formulas. You should be able to apply them both. Wolframalpha gives the answer as just the second formula. Also, when i try to equate them, there are no roots (i.e. they are nowhere near as equal)

Answer 21

also, if you try to type the integral without the square root, wolframalpha uses the log formula

Answer 22

don't get me wrong, i can do integrals perfectly, I was just wondering why that is the case here

Answer 23

It's \(\Large\int\frac{du}u\) which is ln(u) instead of \(\Large\int\frac{du}{\sqrt u}\)

Answer 24

You can view \(\Large\int\frac{du}{\sqrt u}\) as \(\Large\int u^{-0.5} du\)

Answer 25

haha, yeah, got it :P

Answer 26

Glad you got it :)