Math problem

[leone]

I'm still laughing at the Access Denied. It's one of 'em confidential government stars, ain't it?

 

[sketchyrx]

New problem

The cost of manufacturing x caseloads of ballpoint bens is

600x^2 + 600x/x^2 +1

dollars. How many caseloads should be manufactured to have and average cost of $25? (Average cost is defined as if c(x) is the cost of producing x units, then c(x)/x is the average cost per unit.)

To get rid of the fraction I multiplied both sides by x^2+1 and my equation became
600x^2+ 600x = 25x^2 +25..... then I combined like terms and set it all equal to zero

=575x^2 +600x-25=0

when I graph this it looks like a 'mostly' straight up and down line to the left of the y-axis. Isn't this a parabola and doesn't is open up downward? You can take away my gold stars now.

 

[Scythe]

could you write that equation again, but with brackets?

 

[sketchyrx]

Okay I hafta go to skool now. Turn in that assignment..... <_<

 

[ActuarialMadness]

Originally posted by sketchyrx@Jan 18 2008, 12:13 AM
New problem

The cost of manufacturing x caseloads of ballpoint bens is

600x^2 + 600x/x^2 +1

dollars. How many caseloads should be manufactured to have and average cost of $25? (Average cost is defined as if c(x) is the cost of producing x units, then c(x)/x is the average cost per unit.)

To get rid of the fraction I multiplied both sides by x^2+1 and my equation became
600x^2+ 600x = 25x^2 +25..... then I combined like terms and set it all equal to zero

=575x^2 +600x-25=0

when I graph this it looks like a 'mostly' straight up and down line to the left of the y-axis. Isn't this a parabola and doesn't is open up downward? You can take away my gold stars now.

Possibly there is no solution depending on how you intend to write the bracket.s

 

[ActuarialMadness]

if c(x) = 600x^2 + 600x/(x^2 + 1)

then the only solution that fits is a negative number.

c(x)/x = 25
600x + 600/(x^2 + 1) = 25
24x + 24/(x^2 + 1) = 1
24x^3 + 24x + 24 = x^2 + 1

24x^3 - x^2 + 24x + 23 = 0

 

[sketchyrx]

Thanks everyone. I got full credit for this extra credit assignment. Right now I have an A. I share that with everyone here.

 

[givemfitz]

Originally posted by sketchyrx@Jan 18 2008, 12:13 AM


when I graph this it looks like a 'mostly' straight up and down line to the left of the y-axis. Isn't this a parabola and doesn't is open up downward? You can take away my gold stars now.

I had to let it go when you said mostly straight line to the left of the y-axis is a parabola. It could be 1/2 a parabola if there were such a thing. :lol: A parabola is what you should've gotten but not what you were describing to my thinking. :wacko:

So congrats and no credit for me.

 

[sketchyrx]

That's why I was confused. I know what a parabola is supposed to look like and which direction is should open up depending on the positive or negative in front of the first term. I probably wasn't looking at it with the correct dimensions in the window. Anyhoo.

There could be a half-parabola. How bout the square root function?

 

[givemfitz]

Yeah.....it's called a curve. :lol: But technically if you were denoting that said curve was exactly half of an existing parabola like you said then yeah.......I guess you could have a halfarabola.

 

[sketchyrx]

I'll talk to my super-nerdy yet super-smart math teacher about that. :lol:

 

[leone]

So who remembers integration?

 

[givemfitz]

and bussing?

 

[Scythe]

Originally posted by sketchyrx@Feb 3 2008, 11:08 PM
There could be a half-parabola. How bout the square root function?

That's only a halfparabola if you tilt your head

 

[leone]

Originally posted by givemfitz@Feb 12 2008, 10:53 PM
and bussing?

Smart ass.

 

[givemfitz]

Well then be specfic.

 

[leone]

Integration in a math thread? Why, I have no idea what I was thinking! :lol:

 

[givemfitz]

I have no idea what you're SAYING.

 

[leone]

Shut up! I hate you! *slams door*

 

[Magilune]

Now look what you did! <_<


:lol: