Question

\[\Huge\int\dfrac{dx}{4+2^x}\]

Answer 1

How you posted this Question ?

Answer 2

What do you mean? I just type in question and open it?

Answer 3

But how did you used Mathematics Equation way in posting question

Answer 4

sorry, still dont understand what you are asking? I'm using Latex, if this is what you want to know

Answer 5

Let u = 2^x

Answer 6

Why are you using latex and not like cotton or polyester?

Answer 7

How did you got latex before posting your question

Answer 8

I just use `\[ anything here \]`...

Answer 9

ok so \(u = 2^x\) and \(du = 2^x\ln 2 dx\), right? but where to sub in for dx?

Answer 10

I'd suggest using u=4+2^x instead.

Answer 11

u = 4+2^x

Answer 12

ye

Answer 13

But this dosent come when I post my questions

Answer 14

but there is no 2^xln2 dx to sub

Answer 15

Well, actually I don't think it matters to be honest, @Loser66 's substitution is just as good.

Answer 16

\[\int\dfrac{dx}{u}\]??

Answer 17

u =2^x --> du = 2^x ln2 dx--> dx = \(\dfrac{du}{2^xln2}=\dfrac {du}{uln2}\)

Answer 18

ok then, right?

Answer 19

wow so thats how you sub, eh? I always though i have to sub both u and du. cool

Answer 20

Yeah, pretty spiffy.

Answer 21

So \[\dfrac{1}{\ln 2}\int\dfrac{du}{u} = \dfrac{\ln|4+2^x|}{\ln2}+C\]

Answer 22

???