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3 years ago

What is the distance between ( 2 1/2, 3) and (1, -3)

Mathematics

1 answer:

belka [17]3 years ago

4 0

Answer:

11.2361

explanation is up

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A company earned 7 million in one year. The following year, the company lost 11 million. Did the company earn or lose money in t

padilas [110]

Answer:lost

Step-by-step explanation:

The first year they earned 7 million, the second year lost 11 million. subtract 7 from 11 and that is a -4 million

$11-7=-4$

3 0

3 years ago

Use green's theorem to compute the area inside the ellipse x252+y2172=1. use the fact that the area can be written as ∬ddxdy=12∫

Pavel [41]

The area of the ellipse $E$ is given by

$\displaystyle\iint_E\mathrm dA=\iint_E\mathrm dx\,\mathrm dy$

To use Green's theorem, which says

$\displaystyle\int_{\partial E}L\,\mathrm dx+M\,\mathrm dy=\iint_E\left(\frac{\partial M}{\partial x}-\frac{\partial L}{\partial y}\right)\,\mathrm dx\,\mathrm dy$

( $\partial E$ denotes the boundary of $E$ ), we want to find $M(x,y)$ and $L(x,y)$ such that

$\dfrac{\partial M}{\partial x}-\dfrac{\partial L}{\partial y}=1$

and then we would simply compute the line integral. As the hint suggests, we can pick

$\begin{cases}M(x,y)=\dfrac x2\\\\L(x,y)=-\dfrac y2\end{cases}\implies\begin{cases}\dfrac{\partial M}{\partial x}=\dfrac12\\\\\dfrac{\partial L}{\partial y}=-\dfrac12\end{cases}\implies\dfrac{\partial M}{\partial x}-\dfrac{\partial L}{\partial y}=1$

The line integral is then

$\displaystyle\frac12\int_{\partial E}-y\,\mathrm dx+x\,\mathrm dy$

We parameterize the boundary by

$\begin{cases}x(t)=5\cos t\\y(t)=17\sin t\end{cases}$

with $0\le t\le2\pi$ . Then the integral is

$\displaystyle\frac12\int_0^{2\pi}(-17\sin t(-5\sin t)+5\cos t(17\cos t))\,\mathrm dt$

$=\displaystyle\frac{85}2\int_0^{2\pi}\sin^2t+\cos^2t\,\mathrm dt=\frac{85}2\int_0^{2\pi}\mathrm dt=85\pi$

###

Notice that $x^{2/3}+y^{2/3}=4^{2/3}$ kind of resembles the equation for a circle with radius 4, $x^2+y^2=4^2$ . We can change coordinates to what you might call "pseudo-polar":

$\begin{cases}x(t)=4\cos^3t\\y(t)=4\sin^3t\end{cases}$

which gives

$x(t)^{2/3}+y(t)^{2/3}=(4\cos^3t)^{2/3}+(4\sin^3t)^{2/3}=4^{2/3}(\cos^2t+\sin^2t)=4^{2/3}$

as needed. Then with $0\le t\le2\pi$ , we compute the area via Green's theorem using the same setup as before:

$\displaystyle\iint_E\mathrm dx\,\mathrm dy=\frac12\int_0^{2\pi}(-4\sin^3t(12\cos^2t(-\sin t))+4\cos^3t(12\sin^2t\cos t))\,\mathrm dt$

$=\displaystyle24\int_0^{2\pi}(\sin^4t\cos^2t+\cos^4t\sin^2t)\,\mathrm dt$

$=\displaystyle24\int_0^{2\pi}\sin^2t\cos^2t\,\mathrm dt$

$=\displaystyle6\int_0^{2\pi}(1-\cos2t)(1+\cos2t)\,\mathrm dt$

$=\displaystyle6\int_0^{2\pi}(1-\cos^22t)\,\mathrm dt$

$=\displaystyle3\int_0^{2\pi}(1-\cos4t)\,\mathrm dt=6\pi$

3 0

3 years ago

lex is saving money because she would like to purchase the new video gaming system that everyone has been talking about. After t

spin [16.1K]

Well one week she'd have 23.50$. So per week you multiply that number by the number of weeks.

I hope this is what you were looking for, the question was a bit confusing.

8 0

3 years ago

4. Calculate the mean of the data set {22, 34, 37, 23, 45, 21, 29, 37}. Round to the nearest tenth.

Simora [160]

Answer:

31.0

Step-by-step explanation:

The mean of a given set of data is the ratio of the sum of the data to the number of units that make up the data set. It is also called the average of the data set.

Given the data set {22, 34, 37, 23, 45, 21, 29, 37}. There are 8 numbers in the set. The total of these numbers

= 22 + 34 + 37 + 23 + 45 + 21 + 29 + 37

= 248

The mean = 248/8

= 31

6 0

3 years ago

How to write 0.038383838 in bar notation?

Annette [7]

Answer:

I think it would be 0.038

with a line over the 38

Step-by-step explanation:

8 0

3 years ago