 0 ( 4x2 - 2) 2 ℮ 2 x dx

Question

amistre64 · Answer

the parser work for latex, not html

amistre64 · Answer

```
<html>

     <what?>

</html>
```

anonymous · Answer

actually its an integral ,i copy pasted it from word

amistre64 · Answer

looks like you are trying to integrate (4x^2-2)^2 , from 2 to 0

amistre64 · Answer

might wanna copy and paste it into notepad first

anonymous · Answer

there is an also exp(-x^2) with limits o to infinity

amistre64 · Answer

the latex for this would be close to:

```
$$\int_{2}^{0}(4x^2-2)^2~dx$$
```

amistre64 · Answer

$$\int_{2}^{0}(4x^2-2)^2~dx$$

but im not to sure where to put the exp() stuff

anonymous · Answer

in multiplication and 0 is lower and infinity is upper limit

amistre64 · Answer

```
$$\int_{0}^{\infty}(4x^2-2)^2~exp(-x^2)~dx$$
```

$$\int_{0}^{\infty}(4x^2-2)^2~exp(-x^2)~dx$$

like this?

anonymous · Answer

yes thats right !! thanks a loti am sorry i dont use latex and i m not familiar but i am thankful to u for helping.i also need help to solve it lol...

amistre64 · Answer

my first thought is by parts, that poly will go to zero after a few turns, and we can always integrate the exp which is just another notation for e^(-x^2)

anonymous · Answer

i think it is an improper integral and may be somr trick is involved .may be something related to complex integration ..may be jordan lemma but i am not able to do it...;(

amistre64 · Answer

$$\begin{matrix}
&&e^{-x^2}\
+&(4x^2-2)^2&-2xe^{-x^2}\
-&2(4x^2-2)(8x)&4x^2e^{-x^2}+-2e^{-x^2}\
+&16(4x^2-2)+16x(8x)&gets~messier\
-&192x^2-32&"\
+&192(2)x&"\
-&19(2)&"\
&0&--\

\end{matrix}$$

amistre64 · Answer

yeah, im not to useful with complex or jordan lemma stuff.  not enough practice or exposure to it

anonymous · Answer

its answer is not zero i also dont know the answer but its between the 4 choices 4pi,8 sqrt pi , 4 sqrt pi , 8 pi.

amistre64 · Answer

if anything, we could expand the poly out, and run it out in pieces

amistre64 · Answer

do you know what the trig equivalent of e^-x^2 would be?

anonymous · Answer

i knw exp(iq)=cosq+i sinq so  something similar to that may be

anonymous · Answer

no it will involve sinh and cosh yes

amistre64 · Answer

the hs look more righter to me

amistre64 · Answer

if it helps to double check to make sure youre on the right track; the answer should be 4 sqrt(pi) http://www.wolframalpha.com/input/?i=integrate+%284x%5E2-2%29%5E2+e%5E%28-x%5E2%29+dx+from+0+to+inf

anonymous · Answer

did u use mathematica for it ?