Question

I have to repost my question because the answers given were wrong :S

Answer 1

that's why u shouldn't trust our answers and question them

Answer 2

and try to understand the solution

Answer 3

so that u can confirm the answer yourself.

Answer 4

Let be a continuous function defined on the interval [2, infinity[ such that
f(4)=14
|f(x)| < x^3+10
and
the integral from 4 to infinity f(x)*e^(-x/4) = -5
Determine the value of:
the integral from 4 to infinity f'(x)*e^(-x/4) = ?

Answer 5

@Mr.Math a little help on a weird calc question?

Answer 6

how would reposting get correct answers?

Answer 7

a) it was late last night, it is possible people were unmotivated
b) no one really explained it
in essence it still remains an unanswered question

Answer 8

Well Zarkon says on the other post to use integration by parts, and I'll put my money on that being right

Answer 9

looks like dumbcow messed up a little on finding du on that post is all
du=e^(-x/4)/4dx

Answer 10

Let be a continuous function defined on the interval [2, infinity[ such that

f(4)=14

|f(x)| < x^3+10
\[\int_{4}^{inf} f(x)*e^{-\frac{1}{4}x} = -5\]
Determine the value of:

\[\int_{4}^{inf} f'(x)*e^{-\frac{1}{4}x} = ?\]

might be more readable

Answer 11

isnt f(x) just x^3+10 then?

Answer 12

here's what I got:\[\int_{4}^{\infty}f'(x)e^{-\frac x4}dx=f(x)e^{-\frac x4}|_{4}^{\infty}+\frac14\int_{4}^{\infty}f(x)e^{-\frac x4}dx\]we know what the value of that last integral is

Answer 13

i am just not sure how to approach this but ill figure it out im sorry for distressing so many people...

Answer 14

looks to be the graph of: f(x) < x^3+10 so hmmm