# Math Help - Intergrals

1. ## Intergrals

I am a bit stuck on this:
(note: | = intergration symbol)

2|6-3|6

Now i think im right at that point. Not sure what to do from there?

2. I don't get very well what you want.

Use some of LaTeX.

See the LaTeX Help forum.

3. $

\left[ 2\int_3^5 6\right] - \left[ 3\int_3^5 6\right]

$

does that make more sense?

4. Yeah a lot.

It's very easy, since

$\int dx=x+k$, then $\int_a^b dx=b-a$

Does that make sense?

5. wait so i say 5-3? what about the 6 and 3 and 2?

6. Originally Posted by taurus
wait so i say 5-3? what about the 6 and 3 and 2?
$2\int_3^5 6 - 3\int_3^5 6$

You're integrating with respect to what?

We'll assume dx.

Thus, $2\cdot [6(5) - 6(3)] - 3\cdot [6(5)-6(3)] = (2\cdot 12) - (3\cdot 12) = 24 - 36 = -12$

7. wait i think i got the question wrong, suppose we have:
$\int_3^5 f(x) dx = 6$, $\int_3^6 f(x) dx = 5$, $\int_3^5 g(x) dx = 6$

now it asks to find the value of the following integrals:
$\int_3^5 2f(x) -3 g(x) dx =$
??
?? any ideas