[Chaky]

Quote:

Originally Posted by pocodolce 2. By using substitution of u=x^2+4x+1, find the integral of: ∫(x+2)(x^2 + 4x + 1)^4 dx

Question 2 first:

Your integral is in respect of x but you need it in respect of u for the substitution to work.

So start by differentiating the expression you are substituting:

du/dx = 2x + 4

You need to use the fractional behaviour of the differential to rearrange this equation:

dx = du/(2x+4)

[Chaky]

Now substitute this into the integral along with the expression for u. So the bit in the second bracket is just u...

∫u^4 (x+2) du/(2x+4)

And can you see how the other bit cancels the (x+2) from the other bracket? This leaves:

∫(1/2) u^4 du

Integrate it and you get:

(1/10) u^5 (+ a constant of integration)

Now substitute back for u:

(1/10) (x^2 + 4x + 1)^5

You can check your answer by differentiating it back.

I'll do the other question later, bit busy right now. You need a diagram!

[Chaky]

Quote:

Originally Posted by pocodolce 1. Find the volume of the solids of revolution formed if the area enclosed between the curves y=x^2 and y=(x-2)^2 is rotated about the x axis? I know I'm supposed to use the formula:

First of all, do you understand why this formula works? I can try to explain it if you want.

[tortoisie]

Quote:

Originally Posted by Lilliana ^ Mode? Kleidung? Damen,- und Herrenbekleidung?

Thank you!

But I still don't understand what "Art Geschäft" means and how is the word different from Kerngeschäft?

[Waldorf]

I would normally would not actually start a thread but I am working on term paper which requires me to conduct interview to anyone who works for fashion industry. Please answer the following questions.

What job you work for?
How did you get this occupation?
Describe a typical day?
What steps did it take to get where you are now?
What are some specific skills needed to be successful in this job?
What is there that gives you personal satisfaction in your job? What are the negatives?
What skills and personal qualifications will help me to get your job?

Thank you and I hope this thread would be helpful as other people who might be working similar to my term paper.

[Lilliana]

well to admit it, these are not words I come across often, if at all. but I would say Art Geschäft means "general branch" like fashion label, and Kerngeschäft is the "core bussiness" like hmm bags for LV.

[tortoisie]

^ Thank you so much!

In that case, I guess Kerngeschäft is Anzug and the new focus on accessories.

And Art Geschäft would be Boss Orange, Boss Selection and etc., right?

Thanks!

[yellowetpink]

Right well.

I need to find out what for example :

1hr 34minutes

is in hours.

How do I convert the minutes to hours?

[stersita]

60 mins -- 1 hour
94 mins -- x hours

x = 94 x 1 / 60 = 1,57 hours

maybe? I'm not exactly sure what you mean

[tortoisie]

34 minutes in fraction is 34/60 hrs

Therefore 1 hr 34 mins = 1 34/60 hrs

I hope that makes sense!

[stersita]

34/60 looks better than 0.57

[tortoisie]

^ Your method looks more easily understandable than mine though .

[Miwi]

Equations.

sin^2x-sin2x=3cos^x

5sin^2x-3sinxcosx-2cos^2x=0


Thanks in advance!

[Miwi]

I made a mistake.
1.) sin² x - sin2x =3cos² x

[Chaky]

Quote:

Originally Posted by °Isa I made a mistake. 1.) sin² x - sin2x =3cos² x

Ewww!

Okay both of your questions actually have a similar solution.

Use the trig identity sin2x = 2 sin x cos x and substitute it in. Also rearrange the equation so all the terms are on one side.

sin² x - 2 sin x cos x - 3cos² x = 0

What you have is a quadratic equation which you can factorise. That's the tough bit!