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3 years ago

5

If three tenths of adults out of a hundred visitors how many adults are there.

1 answer:

vivado [14]3 years ago

3 0

30 adults because if there are 3/10 it means they reduced so if the denominator is 100 then 30/100 is the answer :)

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Write in slope intercept form . y+4=−12(x−2)

inna [77]

Answer:

20

Step-by-step explanation:

y+4=−12(x−2)

Step 1: Add -4 to both sides.

y+4+−4=−12x+24+−4

y=−12x+20

6 0

3 years ago

Read 2 more answers

Although retirement is far in your future, it is important to start planning early.

nydimaria [60]

Answer: I would say true.

explanation: Because planning on where you want to work you’ll want to see all the benefits and things you’ll be getting into.

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3 years ago

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Use the Divergence Theorem to evaluate S F · dS, where F(x, y, z) = z2xi + y3 3 + sin z j + (x2z + y2)k and S is the top half of

GenaCL600 [577]

Close off the hemisphere $S$ by attaching to it the disk $D$ of radius 3 centered at the origin in the plane $z=0$ . By the divergence theorem, we have

$\displaystyle\iint_{S\cup D}\vec F(x,y,z)\cdot\mathrm d\vec S=\iiint_R\mathrm{div}\vec F(x,y,z)\,\mathrm dV$

where $R$ is the interior of the joined surfaces $S\cup D$ .

Compute the divergence of $\vec F$ :

$\mathrm{div}\vec F(x,y,z)=\dfrac{\partial(xz^2)}{\partial x}+\dfrac{\partial\left(\frac{y^3}3+\sin z\right)}{\partial y}+\dfrac{\partial(x^2z+y^2)}{\partial k}=z^2+y^2+x^2$

Compute the integral of the divergence over $R$ . Easily done by converting to cylindrical or spherical coordinates. I'll do the latter:

$\begin{cases}x(\rho,\theta,\varphi)=\rho\cos\theta\sin\varphi\\y(\rho,\theta,\varphi)=\rho\sin\theta\sin\varphi\\z(\rho,\theta,\varphi)=\rho\cos\varphi\end{cases}\implies\begin{cases}x^2+y^2+z^2=\rho^2\\\mathrm dV=\rho^2\sin\varphi\,\mathrm d\rho\,\mathrm d\theta\,\mathrm d\varphi\end{cases}$

So the volume integral is

$\displaystyle\iiint_Rx^2+y^2+z^2\,\mathrm dV=\int_0^{\pi/2}\int_0^{2\pi}\int_0^3\rho^4\sin\varphi\,\mathrm d\rho\,\mathrm d\theta\,\mathrm d\varphi=\frac{486\pi}5$

From this we need to subtract the contribution of

$\displaystyle\iint_D\vec F(x,y,z)\cdot\mathrm d\vec S$

that is, the integral of $\vec F$ over the disk, oriented downward. Since $z=0$ in $D$ , we have

$\vec F(x,y,0)=\dfrac{y^3}3\,\vec\jmath+y^2\,\vec k$

Parameterize $D$ by

$\vec r(u,v)=u\cos v\,\vec\imath+u\sin v\,\vec\jmath$

where $0\le u\le 3$ and $0\le v\le2\pi$ . Take the normal vector to be

$\dfrac{\partial\vec r}{\partial v}\times\dfrac{\partial\vec r}{\partial u}=-u\,\vec k$

Then taking the dot product of $\vec F$ with the normal vector gives

$\vec F(x(u,v),y(u,v),0)\cdot(-u\,\vec k)=-y(u,v)^2u=-u^3\sin^2v$

So the contribution of integrating $\vec F$ over $D$ is

$\displaystyle\int_0^{2\pi}\int_0^3-u^3\sin^2v\,\mathrm du\,\mathrm dv=-\frac{81\pi}4$

and the value of the integral we want is

(integral of divergence of <em>F</em>) - (integral over <em>D</em>) = integral over <em>S</em>

==> 486π/5 - (-81π/4) = 2349π/20

5 0

3 years ago

The sum of two numbers is 19. Their difference is 65. What are the numbers?

Ludmilka [50]

X = 42 and y = - 23 are the two numbers

3 0

3 years ago

Write an equation of the line that passes through (2001, 35) and (2004.5, 16.1 ) points

Allisa [31]

Answer: If you are looking for Slope-Intercept form (y=mx+b), It would be...

y=-5.4x+10840.4.

If you are looking for Point-Slope form, it would be...

y=-5.4x+10840.4.

Step-by-step explanation: Write in Slope-Intercept from, y=mx+b.

Point-Slope form : Use the Point-Slope formula, y-y1=m(x-x1) to find the equation of the line.

I hope this helps you out! ☺

7 0

3 years ago