Question

Hello everybody!
Any idea for find the integral of (e^x)(ln x)/(x^2+1) dx

Answer 1

is this the question
$$
\Large \int \frac{e^x \cdot ln(x) }{x^2 + 1 } dx

$$

Answer 2

Yes!
\[\int\limits \frac{e^x \ln x }{ x^2+1 }dx\]

Answer 3

good luck with that program
i really really doubt you are going to find a closed form for that integral

Answer 4

lets try the wolf

Answer 5

I really have 4 exercises looking like this, but this is the easiest.

Answer 6

http://www.wolframalpha.com/input/?i= \int+\frac{e^x++ln%28x%29+}{x^2+%2B+1+}+dx

Answer 7

nope

Answer 8

is that the exact question?

Answer 9

I tried with Geogebra too but nothing!

Answer 10

Yes, it's the question.

Answer 11

i would say no way

Answer 12

Wait, there's something more

Answer 13

But derivative is about x and integral is about t, what can be done here?

Answer 14

you dont need to know the antiderivative

Answer 15

$$
\Large \frac{d}{dx}\int_{a}^{x} f(t)~ dt = f(x)

$$

Answer 16

That's because with t=a we have the derivative of a constant value and with t=x we got the same expression...
And now I can see it!
Thanks a lot, I must be so tired to work!

Answer 17

i wish i could do calculus :(

Answer 18

@perl teach me plez...

Answer 19

exactly :)

Answer 20

acx ok :)

Answer 21

another year perl ;)
and i will be there waiting for u to teach ;)

Answer 22

sure

Answer 23

$$
\Large{ \frac{d}{dx}\int_{a}^{x} f(t)~ dt\\
= \frac{d}{dx} [F(x) - F(a)] = \frac{d}{dx}F(x) -\frac{d}{dx}F(a) \\
= F ' (x) - 0 = f(x)

}
$$