How can you help this student make sense of her method? <br> ONLY ANSWER IF YOU KNOW THE ANSWER

Let f(x)=5/x and g(x) =2x^2+5x. What two numbers are not in the domain of F o G?

expeople1 [14]

F(x)=5/x
g(x)=2(x^2)+5x
f(x) has a domain of all real numbers excluding zero
g(x) has a domain of all real numbers
fog(x)=5/(2(x^2)+5x)
fog(x)=5/(x(2x+5))
fog(x) has a domain that excludes both zero and -5/2

6 0

3 years ago

Hyperloop, a new mode of travel, aims to reach a speed of 170170 \dfrac{\text{m}}{\text{s}} s m . This is 50\%50% less than th

liraira [26]

Answer:

Speed of sound is 340 meter per second.

Step-by-step explanation:

Let the speed of sound = x meter per second.

It is given that,

The new mode of travel has the speed 170 meter per second, which is 50% less than the speed of sound.

So, we get,

x - 50%x = 170

i.e. x - 0.5x = 170

i.e. 0.5x = 170

i.e. x = 340 meter per second

Hence, the speed of sound is 340 meter per second.

7 0

3 years ago

Will mark as brainliest to whoever first gets it correct!

anzhelika [568]

Answer: 27 candles.

Step-by-step explanation:

A rectangular prism has a volume calculated by length x width x height.

In this case, the candles have a volume of 220 cm³.

If the company used 5940 cm³ of wax, to find how many candles they made, you just divide them:

$5940 / 220 = 27$

You get 27 candles.

7 0

3 years ago

What fraction of the students in the class named baseball their favorite sport

mojhsa [17]

now, let's take a peek at the denominators, we have 3 and 8 and 12, we can get an LCD of 24 from that.

Let's multiply both sides by the LCD of 24, to do away with the denominators.

so, let's recall that a whole is "1", namely 500/500 = 1 = whole, or 5/5 = 1 = whole or 24/24 = 1 = whole. So the whole class will yield a fraction of 1/1 or just 1.

$\bf ~\hspace{7em}\stackrel{\textit{basketball}}{\cfrac{1}{3}}+\stackrel{\textit{soccer}}{\cfrac{1}{8}}+\stackrel{\textit{football}}{\cfrac{5}{12}}+\stackrel{\textit{baseball}}{x}~=~\stackrel{\textit{whole}}{1} \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ \stackrel{\textit{multiplying both sides by }\stackrel{LCD}{24}}{24\left(\cfrac{1}{3}+\cfrac{1}{8}+\cfrac{5}{12}+x \right)=24(1)}\implies (8)1+(3)1+(2)5+(24)x=24 \\\\\\ 8+3+10+24x=24\implies 21+24x=24\implies 24x=3 \\\\\\ x=\cfrac{3}{24}\implies x=\cfrac{1}{8}$

4 0

3 years ago

A data mining routine has been applied to a transaction dataset and has classified 88 records as fraudulent (30 correctly so) an

chubhunter [2.5K]

Answer:

The classification matrix is attached below

Part a

The classification error rate for the records those are truly fraudulent is 65.91%.

Part b

The classification error rate for records that are truly non-fraudulent is 96.64%

Step-by-step explanation:

The classification matrix is obtained as shown below:

The transaction dataset has 30 fraudulent correctly classified records out of 88 records, that is, 30 records are correctly predicted given that an instance is negative.

Also, there would be 88 - 30 = 58 non-fraudulent incorrectly classified records, that is, 58 records are incorrectly predicted given that an instance is positive.

The transaction dataset has 920 non-fraudulent correctly classified records out of 952 records, that is, 920 records are correctly predicted given that an instance is positive.

Also, there would be 952 - 920 = 32 fraudulent incorrectly classified records, that is, 32 records incorrectly predicted given that an instance is negative.

That is,

Predicted value

Active value Fraudulent Non-fraudulent

Fraudlent 30 58

non-fraudulent 32 920

The classification matrix is obtained by using the information related to the transaction data, which is classified into fraudulent records and non-fraudulent records.

The error rate is obtained as shown below:

The error rate is obtained by taking the ratio of $\left( {b + c} \right)(b+c)$ and the total number of records.

The classification matrix is, shown above

The total number of records is, $30 + 58 + 32 + 920 = 1,040$

The error rate is,

$\begin{array}{c}\\{\rm{Error}}\,{\rm{rate}} = \frac{{b + c}}{{{\rm{Total}}}}\\\\ = \frac{{58 + 32}}{{1,040}}\\\\ = \frac{{90}}{{1,040}}\\\\ = 0.0865\\\end{array}$

The percentage is $0.0865 \times 100 = 8.65$

(a)

The classification error rate for the records those are truly fraudulent is obtained by taking the rate ratio of b and $\left( {a + b} \right)(a+b)$ .

The classification error rate for the records those are truly fraudulent is obtained as shown below:

The classification matrix is, shown above and in the attachment

The error rate for truly fraudulent is,

$\begin{array}{c}\\FP = \frac{b}{{a + b}}\\\\ = \frac{{58}}{{30 + 58}}\\\\ = \frac{{58}}{{88}}\\\\ = 0.6591\\\end{array}$

The percentage is, $0.6591 \times 100 = 65.91$

(b)

The classification error rate for records that are truly non-fraudulent is obtained by taking the ratio of d and $\left( {c + d} \right)(c+d)$ .

The classification error rate for records that are truly non-fraudulent is obtained as shown below:

The classification matrix is, shown in the attachment

The error rate for truly non-fraudulent is,

$\begin{array}{c}\\TP = \frac{d}{{c + d}}\\\\ = \frac{{920}}{{32 + 920}}\\\\ = \frac{{920}}{{952}}\\\\ = 0.9664\\\end{array}$

The percentage is, $0.9664 \times 100 = 96.64$

8 0

3 years ago

How can you help this student make sense of her method? ONLY ANSWER IF YOU KNOW THE ANSWER