Question 1................

What I need to do with this problems

alina1380 [7]

Answer:

L x W x H =Area

Step-by-step explanation:

8 0

3 years ago

Use the divergence theorem to calculate the surface integral s f · ds; that is, calculate the flux of f across s. f(x, y, z) = x

valkas [14]

$\mathbf f(x,y,z)=x^4\,\mathbf i-x^3z^2\,\mathbf j+4xy^2z\,\mathbf k$
$\mathrm{div}(\mathbf f)=\dfrac{\partial(x^4)}{\partial x}+\dfrac{\partial(-x^3z^2)}{\partial y}+\dfrac{\partial(4xy^2z)}{\partial z}=4x^3+0+4xy^2=4x(x^2+y^2)$

Let $\mathcal D$ be the region whose boundary is $\mathcal S$ . Then by the divergence theorem,

$\displaystyle\iint_{\mathcal S}\mathbf f\cdot\mathrm d\mathbf S=\iiint_{\mathcal D}4x(x^2+y^2)\,\mathrm dV$

Convert to cylindrical coordinates, setting

$x=r\cos\theta$
$y=r\sin\theta$

and keeping $z$ as is. Then the volume element becomes

$\mathrm dV=r\,\mathrm dr\,\mathrm d\theta\,\mathrm dz$

and the integral is

$\displaystyle\iiint_{\mathcal D}4x(x^2+y^2)\,\mathrm dV=\int_{\theta=0}^{\theta=2\pi}\int_{r=0}^{r=1}\int_{z=0}^{z=r\cos\theta+7}4r\cos\theta\cdot r^2\cdot r\,\mathrm dz\,\mathrm dr\,\mathrm d\theta$
$=\displaystyle4\iiint_{\mathcal D}r^4\cos\theta\,\mathrm dz\,\mathrm dr\,\mathrm d\theta$
$=\dfrac{2\pi}3$

4 0

3 years ago

I need help with 7-14

aliina [53]

7: $200<3x-y(28) where x represents each kids money out of it and y represents the parents pay.
8: 7.00>(is greater then or equal to) 0.75X + 1.29Y where X is the amount of bagels and Y is the amount of cream cheese containers.
9: $25 + $75>4X where X is the shirts
10: 720-120>(greater then or equal to) 32X where X is the number of people in each row
11: 2400= 2100+ X(1/20) where X is the value of all things sold.
12: 2000<(X7)-668 where X is the amount of cans in one day.
13: 100> 7X - 10Y where X equals the amount of months and Y equals the amount of CD's
14: $80 - $22> (greater than or equal to) 17X where x equals the amount of shirts.

first off sorry it took so long to answer, these long word questions are time consuming and i havent done them in a while so i had to refresh my memory, secondly the equations all end where i say the word "where", thirdly i am absolutely sure of all these answers except for the first one, the first one i am pretty sure i still got it but not 100%.

hope this helps.

5 0

3 years ago

Can someone help me round these two numbers? I completely forgot how ‍

tigry1 [53]

Answer:

Step-by-step explanation:

If you are rounding to nearest tenth

2.6 1.9

Nearest hundredth

2.6 1.87

If the number to the right of the one you want to round is 5 or above, you go up a number. If it's below, you go down 1.

Hope this helps.

5 0

2 years ago

There’s this one as well

Doss [256]

Answer:

V= area of cross-section x length

V = 0.5x(8x9) x 11

V = 396cm^3

Hope this helps!

6 0

2 years ago