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2 years ago

Match each type of vector reflection with the matrix used to achieve it

Mathematics

1 answer:

ElenaW [278]2 years ago

3 0

Let us try reflecting (2,3) about x=y and across x-axis and y-axis.

If we are reflecting about y=x, that means both x,y values will be interchanged that is (2,3) will become (3,2)and this will be achieved by $\left[\begin{array}{cc}0&1\\1&0\end{array}\right]$ .

And for reflection across x-axis,y-value will be multiplied by -1.That is (2,3) becomes (2,-3) and the matrix used to achieve it is $\left[\begin{array}{cc}1&0\\0&-1\end{array}\right]$ .

For reflection across y-axis, x-value will be multiplied by -1. That is (2,3) becomes (-2,3) when reflected across y-axis. The matrix used to achieve it will have -1 in the first place that is $\left[\begin{array}{cc}-1&0\\0&1\end{array}\right]$

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Find the area of the shaded portion in the equilateral triangle with sides 6. Show all work for full credit. (Hint: Assume that

Vadim26 [7]

So... if you notice the picture below

each circle, has their central angle at the vertex of the triangle
that simply means, 3 circles with a radius of 3, overlapping the triangle

now, the area in the middle, the shaded one, will be, the whole area of the triangle MINUS those 3 circle sectors

hmmmm each sector has 60°, that means, all three of them will then be 60+60+60 or 180°, so the area of those three sectors, can be combined into a 180° sector, well, hell, 180° is really half a circle

so.... the area of those three sectors of 60° each, all three combined, is the same area of half a circle with a radius of 3

so $\bf \textit{area of an equilateral triangle}\\\\
A=\cfrac{s^2\sqrt{3}}{4}\qquad s=\textit{length of one side}\\\\
-----------------------------\\\\
\textit{area of a circle}\\\\
A=\pi r^2\qquad r=radius\\\\
\textit{area of half a circle}\\\\
A=\cfrac{\pi r^2}{2}\\\\
-----------------------------\\\\$

$\bf \textit{now, let us use the side of 6, and radius of 3}
\\\\\\

\begin{array}{clclll}
\cfrac{6^2\sqrt{3}}{4}&-&\cfrac{\pi 3^2}{2}\\
\uparrow &&\uparrow \\
triangle's&&semi-circle's
\end{array}\impliedby \textit{area of shaded area}\\\\
-----------------------------\\\\
\boxed{\cfrac{36\sqrt{3}}{4}-\cfrac{9\pi }{2}}$

you can, add the fractions if you want, or leave them like that, or get their difference by using their decimal format

8 0

2 years ago

Read 2 more answers

#6) Beth saved a total of $30 per month for her first car. Beth saved

cluponka [151]

Answer:

1) The domain In interval notation is [0, 20]

2) The range in interval notation is [100, 700]

Step-by-step explanation:

The given parameters are;

The amount Beth saved per month = $30

The number of months Beth saved = 20 months

The amount with which Beth opened her account = $100

Therefore, the amount of money Beth saved with respect to time is given as follows;

Y = $100 + $30 × X

Where;

Y = The amount of money Beth saved

X = The time (number of months) Beth saved

The domain is given as follows;

$\{X | \ 0 \leq X \leq 20 \}$

The domain in interval notation is [0, 20]

For the range, when X = 0, Y = $100

When X = 20, Y = $100 + $30 × 20 = $700

Therefore, the range is given as follows;

$\{Y | \ 100 \leq Y \leq 700 \}$

Which the range in interval notation is [100, 700].

6 0

2 years ago

The table shows the estimated number of lines of code written by computer programmers per hour when x people are working.

PilotLPTM [1.2K]

Answer:

Hence, the model that best represents the data is:

$y=26.9x-1.3$

Step-by-step explanation:

We are given a table that shows the estimated number of lines of code written by computer programmers per hour when x people are working.

We are asked to find which model best represents the data?

So for finding this we will put the value of x in each of the functions and check which hold true that which gives the value of y i.e. f(x) as is given in the table:

We are given 4 functions as:

$y = 47(1.191)^x$

$y=34\times (1.204)^x$

$y=26.9x-1.3$

$y=27x-4$

We make the table of these values at different values of x.

x A B C D

2 66.66 49.3 52.5 50

4 94.57 71.44 106.3 104

6 134.14 103.57 160.1 158

8 190.27 150.14 213.9 212

10 269.91 217.64 267.7 266

12 382.85 315.5 321.5 320.

Hence, the function that best represents the data is:

Option C.

y=26.9x-1.3

6 0

2 years ago

Read 2 more answers

Bob wants to plant a 7 foot by 10 foot garden with a uniform border of petunias around the outside and still have 28 square feet

skelet666 [1.2K]

Answer:

1.5 feet

Step-by-step explanation:

Bob wants to plant a 7 foot by 10 foot garden.

Area = $7\times10=70$ square feet

He wants to make a uniform border of petunias around the outside and still have 28 square feet to plant tomatoes and roses in the middle.

Means we have to factor 28 in a way that the length and width is less than 10 and 7.

28 = 2 x 2 x 7

Means 4 feet can be width and 7 feet the length of the area where tomatoes need to be planted.

So, we have $10-7=3$ feet less than outer garden means at each side $3/2=1.5$ feet decreases.

Similarly, we have $7-4=3$ feet less width and at each side it is 1.5 feet.

Therefore, the border of petunias will be 1.5 feet wide on all sides.

4 0

2 years ago

Read 2 more answers

Over the past decade, the mean number of hacking attacks experienced by members of the Information Systems Security Association

fredd [130]

Answer:

$P(X>600)=P(\frac{X-\mu}{\sigma}>\frac{600-\mu}{\sigma})=P(Z>\frac{600-510}{14.28})=P(z>6.302)$

And we can find this probability using the complement rule and the normal standard distribution and we got:

$P(z>6.302)=1-P(z$

Step-by-step explanation:

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".

Solution to the problem

Let X the random variable that represent the number of attacks of a population, and for this case we know the distribution for X is given by:

$X \sim N(510,14.28)$

Where $\mu=510$ and $\sigma=14.28$

We are interested on this probability

$P(X>600)$

And the best way to solve this problem is using the normal standard distribution and the z score given by:

$z=\frac{x-\mu}{\sigma}$

If we apply this formula to our probability we got this:

$P(X>600)=P(\frac{X-\mu}{\sigma}>\frac{600-\mu}{\sigma})=P(Z>\frac{600-510}{14.28})=P(z>6.302)$

And we can find this probability using the complement rule and the normal standard distribution and we got:

$P(z>6.302)=1-P(z$

7 0

2 years ago