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2 years ago

12

100 points!!!!!!!! A box contains 8 rings, 10 necklaces, and 4 pins. If Anya selects 1 piece at random, does NOT replace it, and

then picks another, what is the probability that she selected 2 rings?

1 answer:

Aliun [14]2 years ago

7 0

Answer:

2/25

Step-by-step explanation:

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Stacy and Neil painted 280 ft^2 of their living room wall with 4/5 gallon of paint. How many square feet can they paint with 3 g

sweet [91]

The answer is 1050 ft^2

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3 years ago

Read 2 more answers

Directions - For the following problem, write a paragraph proof to justify each step you make. All work must be neat,

nlexa [21]

$$ PS = \frac{4}{3} x$

Solution:

Given PRQ is a triangle.

ST is a line parallel to RQ.

$$PT = x, \ PQ = 3x, \ SR=\frac{8}{3}x$

$TQ=PQ-PT$

$TQ=3x -x=2x$

<u>Triangle proportionality theorem,</u>

<em>If a line parallel to one side of a triangle intersects the other two sides, then it divides the two sides proportionally.</em>

$$\frac{PS}{SR} =\frac{PT}{TQ}$

$$\frac{PS}{\frac{8}{3} x} =\frac{x}{2x}$

Do cross multiplication, we get

$$ PS \times 2x=x \times \frac{8}{3} x$

Divide by 2x on both sides, we get

$$ PS = \frac{4}{3} x$

4 0

2 years ago

Can I get help with finding the Fourier cosine series of F(x) = x - x^2

trapecia [35]

Assuming you want the cosine series expansion over an arbitrary symmetric interval $[-L,L]$ , $L\neq0$ , the cosine series is given by

$f_C(x)=\dfrac{a_0}2+\displaystyle\sum_{n\ge1}a_n\cos nx$

You have

$a_0=\displaystyle\frac1L\int_{-L}^Lf(x)\,\mathrm dx$
$a_0=\dfrac1L\left(\dfrac{x^2}2-\dfrac{x^3}3\right)\bigg|_{x=-L}^{x=L}$
$a_0=\dfrac1L\left(\left(\dfrac{L^2}2-\dfrac{L^3}3\right)-\left(\dfrac{(-L)^2}2-\dfrac{(-L)^3}3\right)\right)$
$a_0=-\dfrac{2L^2}3$

$a_n=\displaystyle\frac1L\int_{-L}^Lf(x)\cos nx\,\mathrm dx$

Two successive rounds of integration by parts (I leave the details to you) gives an antiderivative of

$\displaystyle\int(x-x^2)\cos nx\,\mathrm dx=\frac{(1-2x)\cos nx}{n^2}-\dfrac{(2+n^2x-n^2x^2)\sin nx}{n^3}$

and so

$a_n=-\dfrac{4L\cos nL}{n^2}+\dfrac{(4-2n^2L^2)\sin nL}{n^3}$

So the cosine series for $f(x)$ periodic over an interval $[-L,L]$ is

$f_C(x)=-\dfrac{L^2}3+\displaystyle\sum_{n\ge1}\left(-\dfrac{4L\cos nL}{n^2L}+\dfrac{(4-2n^2L^2)\sin nL}{n^3L}\right)\cos nx$

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3 years ago

The saucer for Aisha's teacup has a diameter of 6 inches. What is the saucer's radius?

Aleonysh [2.5K]

I think its 6 but im not sure to be exactly right

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2 years ago

An artist wants to frame a square painting with an area of 400 square inches . she wants

Artemon [7]

(a) $x^{2}$ = 400
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2 years ago