Evaluate tan 11 pi over 6

A rectangle with vertices A(6, 0), K(0,0), L(0,9), and M(6, 9) is rotated around the x-axis. To the nearest tenth of a cubic uni

koban [17]

Answer:

1526.0 cubic units

Step-by-step explanation:

Rotating rectangle AKLM you will get cylinder with height KA and base radius KL. From the given data

$KA=\sqrt{(6-0)^2+(0-0)^2}=6,\\ \\KL=\sqrt{(0-0)^2+(9-0)^2}=9.$

The volume of the cylinder is

$V_{cylinder}=\pi r^2\cdot H.$

Then

$V_{cylinder}=\pi \cdot 9^2\cdot 6=486\pi \approx 1526.0\ un^3.$

7 0

2 years ago

The radius of a cone is increasing at a constant rate of 7 meters per minute, and the volume is decreasing at a rate of 236 cubi

storchak [24]

Answer:

The rate of change of the height is 0.021 meters per minute

Step-by-step explanation:

From the formula

$V = \frac{1}{3}\pi r^{2}h$

Differentiate the equation with respect to time t, such that

$\frac{d}{dt} (V) = \frac{d}{dt} (\frac{1}{3}\pi r^{2}h)$

$\frac{dV}{dt} = \frac{1}{3}\pi \frac{d}{dt} (r^{2}h)$

To differentiate the product,

Let r² = u, so that

$\frac{dV}{dt} = \frac{1}{3}\pi \frac{d}{dt} (uh)$

Then, using product rule

$\frac{dV}{dt} = \frac{1}{3}\pi [u\frac{dh}{dt} + h\frac{du}{dt}]$

Since $u = r^{2}$

Then, $\frac{du}{dr} = 2r$

Using the Chain's rule

$\frac{du}{dt} = \frac{du}{dr} \times \frac{dr}{dt}$

∴ $\frac{dV}{dt} = \frac{1}{3}\pi [u\frac{dh}{dt} + h(\frac{du}{dr} \times \frac{dr}{dt})]$

Then,

$\frac{dV}{dt} = \frac{1}{3}\pi [r^{2} \frac{dh}{dt} + h(2r) \frac{dr}{dt}]$

Now,

From the question

$\frac{dr}{dt} = 7 m/min$

$\frac{dV}{dt} = 236 m^{3}/min$

At the instant when $r = 99 m$

and $V = 180 m^{3}$

We will determine the value of h, using

$V = \frac{1}{3}\pi r^{2}h$

$180 = \frac{1}{3}\pi (99)^{2}h$

$180 \times 3 = 9801\pi h$

$h =\frac{540}{9801\pi }$

$h =\frac{20}{363\pi }$

Now, Putting the parameters into the equation

$\frac{dV}{dt} = \frac{1}{3}\pi [r^{2} \frac{dh}{dt} + h(2r) \frac{dr}{dt}]$

$236 = \frac{1}{3}\pi [(99)^{2} \frac{dh}{dt} + (\frac{20}{363\pi }) (2(99)) (7)]$

$236 \times 3 = \pi [9801 \frac{dh}{dt} + (\frac{20}{363\pi }) 1386]$

$708 = 9801\pi \frac{dh}{dt} + \frac{27720}{363}$

$708 = 30790.75 \frac{dh}{dt} + 76.36$

$708 - 76.36 = 30790.75\frac{dh}{dt}$

$631.64 = 30790.75\frac{dh}{dt}$

$\frac{dh}{dt}= \frac{631.64}{30790.75}$

$\frac{dh}{dt} = 0.021 m/min$

Hence, the rate of change of the height is 0.021 meters per minute.

3 0

2 years ago

8/x=14/7 what does x equal

Veronika [31]

Answer:

when you have two fractions that equal each other you want to solve by using cross multiply

What cross multiply is, is when you multiply diagonally so:

8/x=14/7

you would take 14*x and 8*7

14x=56 (you would then divide each side by 14)

x=4 (14/14=1, 56/14=4)

8/4=14/7

To check your work you could simplify

8/4=2

14/7=2

2=2, which is true

x=4

Hope this helps ;)

6 0

2 years ago

ΔABC and ΔXYZ are similar triangles. The lengths of two sides of each triangle are shown. Find the lengths of the third side of

Norma-Jean [14]

Answer:

b=9

x=5.5

Step-by-step explanation:

find the common ration

AB is 6, and XY is 3 (they are the corresponding sides)

ratio is 2 to 1 (6/3=2/1)

AC corresponds with YZ

XY is 4.5 so b is 4.5*2=9

ZY corresponds with CB

CB is 11, since XYZ is the smaller divide by 2 instead of multiplying by 2

4 0

2 years ago

Which expression is equal to 632?

Taya2010 [7]

Answer:

2*316

Step-by-step explanation:

7 0

2 years ago