last calculus final question

[stoops the eternal pimp]

The marginal demand for a product is given by
D′(p) = -742/p^2/3
,
where p is the price of the item. Find the demand function, given that
2042 units are demanded when the price is $4.00.

Vet I know you know!

[olevetonahill]

Water melon is Higher priced than ***** !

[stoops the eternal pimp]

Thats it....YOU DA MAN

[olevetonahill]

Next question .:D

[olevetonahill]

I bet I can work a Slide Rule Better than you !
Hell I bet I got one , And you aint ever seen one .:P

[Turd_Ferguson]

Water melon is Higher priced than ***** !DAMMIT!!!:mad: I had it right on the end of mah toungue, tung, tonge....whatever.:D

[stoops the eternal pimp]

I may start drinking tonight

[olevetonahill]

DAMMIT!!!:mad: I had it right on the end of mah toungue, tung, tonge....whatever.:D

Go on :hot:

[Turd_Ferguson]

Go on :hot::mad:











:D

[olevetonahill]

I may start drinking tonight

You evar get a weapon ?
I got 42 acres Of hill you can shoot up.
Oh and I have been an instructor , dont tell every body tho ;)

[olevetonahill]

:mad:











:D

You opened the door
I just strolled Thru lol

[Frozen Sooner]

The marginal demand for a product is given by
D′(p) = -742/p^2/3
,
where p is the price of the item. Find the demand function, given that
2042 units are demanded when the price is $4.00.

Vet I know you know!

OK, so rewrite the problem.

dD(p)/dp=-742(p^-2/3)
dD(p)=-742(p^-2/3)dp
D(P)=-2226p^(1/3)+C

D(4)=2042=-2226(4)^(1/3)+C

Solve for C (sorry, don't have a calculator that'll do cubes here.)

Then plug C into D(p)=-2226^(1/3)+C

[yermom]

i'm either looking at that wrong, or the numbers are way irrational

[stoops the eternal pimp]

Gonna contact Dean and see about gettin something soon....


15 hours of college + 2 jobs+a wife and 2 kids to take care of =insanity

[olevetonahill]

OK, so rewrite the problem.

dD(p)/dp=-742(p^-2/3)
dD(p)=-742(p^-2/3)dp
D(P)=-2226p^(1/3)+C

D(4)=2042=-2226(4)^(1/3)+C

Solve for C (sorry, don't have a calculator that'll do cubes here.)

Then plug C into D(p)=-2226^(1/3)+C

Smartass :P
:pop:

[Turd_Ferguson]

i'm either looking at that wrong, or the numbers are way irrationalIf it's one thing I can't stand, it's irrational numbers:mad:

[olevetonahill]

i'm either looking at that wrong, or the numbers are way irrational

Use yer Slide Rule :D

[yermom]

ok, i was looking at it wrong AND the numbers are irrational :D

[olevetonahill]

ok, i was looking at it wrong AND the numbers are irrational :D

Thats Just irrational !:confused:

[Turd_Ferguson]

Use yer Slide Rule :DGo on:hot:












:D

[olevetonahill]

If it's one thing I can't stand, it's irrational numbers:mad:

I have a Hard time understandin Rational Numbers !

[SteelClip49]

so, that's how the BCS formula works...now I understand.

[soonermix]

The marginal demand for a product is given by
D′(p) = -742/p^2/3
,
where p is the price of the item. Find the demand function, given that
2042 units are demanded when the price is $4.00.

Vet I know you know!

D = Diploma... i'm out

[tommieharris91]

so, that's how the BCS formula works...now I understand.

No, that requires at least Calc 4.

[olevetonahill]

Go on:hot:












:D

http://www.hpmuseum.org/powerlog.jpg
Back In the Day
Id be In class , Hold the Rule In my Lap and slowly slide It up an Down as I winked at the Hawt chick .:hot:
Oh hell I gotta go Be right Back
Fond Mammeries .

[Frozen Sooner]

i'm either looking at that wrong, or the numbers are way irrational

Well, it probably would have helped if I had put the brackets around the -2/3 instead of p^-2/3.

[soonerboomer93]

5

[yermom]

Well, it probably would have helped if I had put the brackets around the -2/3 instead of p^-2/3.

i was responding to the original poster, i just took long enough poking around with that problem that everyone had already posted by the time i did

i was multiplying by 1/3 instead of dividing was my problem

oh and google will act like a calculator :P

http://www.google.com/search?q=4%5E%281%2F3%29&

[VeeJay]

My advice to you would be do drink heavily.

[SanJoaquinSooner]

Here's one of my favorite Calc I problems.


A powerhouse is on one edge of a straight river and a factory is on the opposite edge, 5 miles downstream.
The river is one mile wide.
It costs $10,000 per mile to run electric cable across the river and $5000 per mile on land.
Find the minimum cost of running cable from the powerhouse to the factory.

[yermom]

i'm having trouble doing that with Calc I methods :O

i'm not sure how it could be less than $35,000 though.

it seems like there is no reason to not go straight across if the river cable costs more than ground cable * 2^(1/2)

EDIT: hmm, now that i look more closely, i guess that's not quite right.

[Frozen Sooner]

Here's one of my favorite Calc I problems.


A powerhouse is on one edge of a straight river and a factory is on the opposite edge, 5 miles downstream.
The river is one mile wide.
It costs $10,000 per mile to run electric cable across the river and $5000 per mile on land.
Find the minimum cost of running cable from the powerhouse to the factory.

cost=10000r+5000l

r=(1+(5-l)^2)^(1/2) by the Pythagorean theorem.

I think that's the way you attack the problem. I have to go to work soon, so I'll leave the rest to you. :D

[Sooner24]

I bet I can work a Slide Rule Better than you !
Hell I bet I got one , And you aint ever seen one .:P

I have my dads old slide rule.

[yermom]

cost=10000r+5000l

r=(1+(5-l)^2)^(1/2) by the Pythagorean theorem.

I think that's the way you attack the problem. I have to go to work soon, so I'll leave the rest to you. :D

seems like you missed a step

[Frozen Sooner]

Which step did I miss? I didn't show a couple of algebraic transformations, true.

But for the sake of completeness:

A right triangle of with one side equal to 1 and the hypoteneuse equal to the run of cable across the river (r) will have the other side equal to the total length of the river from power station to the factory minus the length of power cable run on land (l)

Therefore, r^2=1^2+(5-l)^2.

r=(1+(5-l)^2)^(1/2)

I think this might be the wrong attack, though, because the numbers get all cruddy.

[yermom]

hmm, maybe i'm confused

i think i see another way to do it though

[yermom]

ok, i was reading you wrong :)


i get about $33,660

[Frozen Sooner]

Yeah, I may be barking up the wrong tree. Like I said, the numbers get all cruddy, because you end up having to take the first derivative of:

c(l)=(10000)(26-10l-l^2)^(1/2)+5000l

And that shart just ain't gonna fly. I guess you could work a substitution of:

u=26-10l-l^2
du=10-2l
-du=2l-10
c(l)=(10000)(26-10l-l^2)^(1/2)+5000l
c(u)=10000(u)^(1/2)+2500du+25000
c'(u)=5000(u)^(-1/2)du+2500ddu
c'(l)=5000(26-10l-l^2)^(-1/2)(2l-10)+2500(-2)
c'(l)=5000(26-10l-l^2)^(-1/2)(2l-10)-5000

Like I said-numbers getting ugly here.

[AggieTool]

The answer is 4.:D

[Frozen Sooner]

The answer is I pitched a fit about the moderation here and left.:D

Fixed

[yermom]

Yeah, I may be barking up the wrong tree. Like I said, the numbers get all cruddy, because you end up having to take the first derivative of:

c(l)=(10000)(26-10l-l^2)^(1/2)+5000l

And that shart just ain't gonna fly. I guess you could work a substitution of:

u=26-10l-l^2
du=10-2l
-du=2l-10
c(l)=(10000)(26-10l-l^2)^(1/2)+5000l
c(u)=10000(u)^(1/2)+2500du+25000
c'(u)=5000(u)^(-1/2)du+2500ddu
c'(l)=5000(26-10l-l^2)^(-1/2)(2l-10)+2500(-2)
c'(l)=5000(26-10l-l^2)^(-1/2)(2l-10)-5000

Like I said-numbers getting ugly here.

where did all those other numbers come from?

i took the first derivative of: C(L) = 5000 * L + 10000 * (1+(5-L)^2)^(1/2)

i got that 5-L = 3^(-1/2)

[BlondeSoonerGirl]

:les: SHOW YER WORK!!!

[Frozen Sooner]

where did all those other numbers come from?

i took the first derivative of: C(L) = 5000 * L + 10000 * (1+(5-L)^2)^(1/2)

i got that 5-L = 3^(-1/2)

I went ahead and expanded (5-L)^2 to 25-10l-l^2

[yermom]

eww

[Frozen Sooner]

Yeah. Not so bright. Your approach is much more elegant.

[AggieTool]

Fixed

Meh, I got bored with the intellectuals on the other forum, so I came here.:D