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2 years ago

The volume of a cylinder of height 8 cm is 72π cm3 Find the radius of the cylinder.

Mathematics

1 answer:

SVEN [57.7K]2 years ago

8 0

Answer:

3 cm

Step-by-step explanation:

Divide the volume by the height

72π/8 = 9π

Now we have the surface area. The surface area is π $r^{2}$ , so we reverse it.

Divide the number by π:

9π/π=9

Now we find the square root

3 x 3 is 9, so 3 is the square root and radius.

You might be interested in

What is the inequality of You must be over 12 years old to ride the go-karts.

Valentin [98]

Answer:

x ≥ 12

Hope that helps!

Step-by-step explanation:

6 0

2 years ago

A skier is trying to decide whether or not to buy a season ski pass. A daily pass costs $65. A season pass costs $400. The skier

Vlad [161]

Let x be the number of days.

Daily pass:
65x + 30x
95x

Season pass:
400 + 30x

95x > 400 + 30x
65x > 400
x > 6.15

The number of days can't be 6.15, so you must round. You can't go down because then the price will be more expensive, so you have to round up.

It would take 7 days until the season pass is less expensive than the daily pass.
----------------------
You can check this by plugging in the x.

95x > 400 + 30x
95(7) > 400 + 30(7)
665 > 400 + 210
665 > 600
The daily pass is more expensive than the season pass.

3 0

2 years ago

A large corporation starts at time t = 0 to invest part of its receipts continuously at a rate of P dollars per year in a fund f

Andrews [41]

Answer:

$A = \frac{P}{r}\left( e^{rt} -1 \right)$

Step-by-step explanation:

This is <em>a separable differential equation</em>. Rearranging terms in the equation gives

$\frac{dA}{rA+P} = dt$

Integration on both sides gives

$\int \frac{dA}{rA+P} = \int dt$

where $c$ is a constant of integration.

The steps for solving the integral on the right hand side are presented below.

$\int \frac{dA}{rA+P} = \begin{vmatrix} rA+P = m \implies rdA = dm\end{vmatrix} \\\\\phantom{\int \frac{dA}{rA+P} } = \int \frac{1}{m} \frac{1}{r} \, dm \\\\\phantom{\int \frac{dA}{rA+P} } = \frac{1}{r} \int \frac{1}{m} \, dm\\\\\phantom{\int \frac{dA}{rA+P} } = \frac{1}{r} \ln |m| + c \\\\&\phantom{\int \frac{dA}{rA+P} } = \frac{1}{r} \ln |rA+P| +c$

Therefore,

$\frac{1}{r} \ln |rA+P| = t+c$

Multiply both sides by $r.$

$\ln |rA+P| = rt+c_1, \quad c_1 := rc$

By taking exponents, we obtain

$e^{\ln |rA+P|} = e^{rt+c_1} \implies |rA+P| = e^{rt} \cdot e^{c_1} rA+P = Ce^{rt}, \quad C:= \pm e^{c_1}$

Isolate $A$ .

$rA+P = Ce^{rt} \implies rA = Ce^{rt} - P \implies A = \frac{C}{r}e^{rt} - \frac{P}{r}$

Since $A = 0$ when $t=0$ , we obtain an initial condition $A(0) = 0$ .

We can use it to find the numeric value of the constant $c$ .

Substituting $0$ for $A$ and $t$ in the equation gives

$0 = \frac{C}{r}e^{0} - \frac{P}{r} \implies \frac{P}{r} = \frac{C}{r} \implies C=P$

Therefore, the solution of the given differential equation is

$A = \frac{P}{r}e^{rt} - \frac{P}{r} = \frac{P}{r}\left( e^{rt} -1 \right)$

4 0

2 years ago

Help me i will give you 50 points

jeyben [28]

1) (f + g)(2) = 7 + 3 = 10 The answer is C

2) (f - g)(4) = 11 - 15 = -4 The answer is A

3) f(1) = 2(1) + 3 = 5 g(1) = 1² - 1 = 0 The answer is D

4) (f xg ) (1) = 7/3 The answer is B

5 0

2 years ago

Read 2 more answers

Help please i need help

Anika [276]

Answer:

OMG what level is this???

Step-by-step explanation:

8 0

2 years ago