Fundamental Theorem of Calculus 1 questioin

Question

thecalchater · Answer

@zepdrix  @dan815

zepdrix · Answer

hehe sec XD about half way through it.
you're too quick for me

thecalchater · Answer

:) I think it may be b just guessing.

zepdrix · Answer

Hmm I'm not getting anything close to these values...
I must be doing something wrong >.<

zepdrix · Answer

Oh this is the mean value theorem for INTEGRALS... not derivatives
wooooops :O back to the drawing board...

thecalchater · Answer

ok XD

zepdrix · Answer

Average value is obtained by$$\large\rm \frac{1}{b-a}\int\limits_a^b f(x)dx=f(c)$$Where c is somewhere between a and b.

zepdrix · Answer

So umm

zepdrix · Answer

$$\large\rm \frac{1}{7-1}\int\limits_1^7\frac{u^2+4}{u^2}du=?$$Understand how to do this integral? :)

thecalchater · Answer

7/396 I got.

irishboy123 · Answer

thecalchater · Answer

any ideas?

perl · Answer

This is basically a plug into integral problem?

thecalchater · Answer

I think so.... @dan815

perl · Answer

on paper I found 11/7

thecalchater · Answer

right that is what i thought too, but I dont know if the mean value is + and - or just +

perl · Answer

We can solve f(u) = 11/7

perl · Answer

i.e. solve (u^2 + 4)/u^2 = 11/7

thecalchater · Answer

it would be both - and + sqrt7 so  D?

perl · Answer

That part is tricky. The directions say that the function is defined for u between 1 and 7. Therefore I would go with just the positive.

thecalchater · Answer

ok let me submit it and see

thecalchater · Answer

I got it right thank you :)

perl · Answer

since it is talking about 'the' interval [1,7]

thecalchater · Answer

it was b  only positive like I had said in the beginning... thanks for the help though

perl · Answer

:)