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2 years ago

If the surface area of a cylinder is given by SA =

Mathematics

1 answer:

Mars2501 [29]2 years ago

7 0

Answer:

The height is 11/2

Step-by-step explanation:

We know SA = 30n

and r = 2

We are solving for h. So plug in our values

30n = 2n(2)^2 + 2n(2)h

Multiply and square on the right side terms

30n = 8n + 4nh

Divide everything by n

30 = 8 + 4h

Subtract 8 on both sides

22 = 4h

Divide by 4 on both sides

h = 22/4 = 11/2

Check:

30n = 2n(2)^2 + 2n(2)(11/2)

30n = 8n + 22n

30n = 30n

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1 A large bottle holds 250% as much water as a small bottle. If the small bottle holds 12 ounces of water, how many ounces of wa

DENIUS [597]

Answer:

30!

Step-by-step explanation:

250% as much

small bottle holds 12 ounces of water

12*2=24+6=30

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2 years ago

Whats the error?katie divided 4.25 by 0.25 and a got a quotient of 0.17.

m_a_m_a [10]

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2 years ago

Suppose that \nabla f(x,y,z) = 2xyze^{x^2}\mathbf{i} + ze^{x^2}\mathbf{j} + ye^{x^2}\mathbf{k}. if f(0,0,0) = 2, find f(1,1,1).

lesya [120]

The simplest path from (0, 0, 0) to (1, 1, 1) is a straight line, denoted $C$ , which we can parameterize by the vector-valued function,

$\mathbf r(t)=(1-t)(\mathbf i+\mathbf j+\mathbf k)$

for $0\le t\le1$ , which has differential

$\mathrm d\mathbf r=-(\mathbf i+\mathbf j+\mathbf k)\,\mathrm dt$

Then with $x(t)=y(t)=z(t)=1-t$ , we have

$\displaystyle\int_{\mathcal C}\nabla f(x,y,z)\cdot\mathrm d\mathbf r=\int_{t=0}^{t=1}\nabla f(x(t),y(t),z(t))\cdot\mathrm d\mathbf r$

$=\displaystyle\int_{t=0}^{t=1}\left(2(1-t)^3e^{(1-t)^2}\,\mathbf i+(1-t)e^{(1-t)^2}\,\mathbf j+(1-t)e^{(1-t)^2}\,\mathbf k\right)\cdot-(\mathbf i+\mathbf j+\mathbf k)\,\mathrm dt$

$\displaystyle=-2\int_{t=0}^{t=1}e^{(1-t)^2}(1-t)(t^2-2t+2)\,\mathrm dt$

Complete the square in the quadratic term of the integrand: $t^2-2t+2=(t-1)^2+1=(1-t)^2+1$ , then in the integral we substitute $u=1-t$ :

$\displaystyle=-2\int_{t=0}^{t=1}e^{(1-t)^2}(1-t)((1-t)^2+1)\,\mathrm dt$

$\displaystyle=-2\int_{u=0}^{u=1}e^{u^2}u(u^2+1)\,\mathrm du$

Make another substitution of $v=u^2$ :

$\displaystyle=-\int_{v=0}^{v=1}e^v(v+1)\,\mathrm dv$

Integrate by parts, taking

$r=v+1\implies\mathrm dr=\mathrm dv$

$\mathrm ds=e^v\,\mathrm dv\implies s=e^v$

$\displaystyle=-e^v(v+1)\bigg|_{v=0}^{v=1}+\int_{v=0}^{v=1}e^v\,\mathrm dv$

$\displaystyle=-(2e-1)+(e-1)=-e$

So, we have by the fundamental theorem of calculus that

$\displaystyle\int_C\nabla f(x,y,z)\cdot\mathrm d\mathbf r=f(1,1,1)-f(0,0,0)$

$\implies-e=f(1,1,1)-2$

$\implies f(1,1,1)=2-e$

3 0

2 years ago

- 4(x + 5) = 16 what does x equal?

qwelly [4]

Answer:x= 9

Step-by-step explanation:

-4(x+5) = 16

-4*x= -4x -4*5= -20

16 - -20= 36

-4x/-4= x 36/-4=9

5 0

2 years ago

Write an equation of the line that passes through the given points.<br> (-1,7) and (4, -8)

djverab [1.8K]

Answer:

y=-3x+4

Step-by-step explanation:

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m=(-8-7)/(4-(-1))

m=-15/(4+1)

m=-15/5

m=-3

y-y1=m(x-x1)

y-7=-3(x-(-1))

y-7=-3(x+1)

y=-3x-3+7

y=-3x+4

3 0

2 years ago