9514 1404 393
Answer:
f'(2) ≈ −1.3508
Step-by-step explanation:
The derivative of the function is ...
f'(x) = 5(-e^-x·ln(x^2 +5x) +e^-x·(2x +5)/(x^2 +5x))
Then ...
f'(2) = 5e^(-2)(-ln(14) +9/14) ≈ -1.3508
A newspaper is launching a new advertising campaign in order to increase the number of daily subscribers. The newspaper currently (t0) has 26,000 daily subscribers and management expects that number, S(t), to grow at the rate of subscribers per day, where t is the number of days since the campaign began. How long (to the nearest day) should the campaign last if the newspaper wants the number of daily subscribers to grow to 49,000?
Answer:
57 days
Step-by-step explanation:
Given that:
t(0) = 26000
Growth rate (S'(t)) = 80t^1/2
Targeted number of subscribers = 49000
Take the integral of the growth rate :
∫80t^1/2dt = [(80t^(1/2 + 1)) / 1/2 + 1] + C
[(80t^(1/2 + 1)) / 1/2 + 1] + C = (80t^3/2) / 3/2 + C
(80t^3/2) * 3/2 + C = (160/3)t^3/2 + C
(160/3)t^3/2 + C
Let C = t(0)
(160/3)t^3/2 + 26000 = 49000
(160/3)t^3/2 = 49000 - 26000
(160/3)t^3/2 = 23000
Multiply both sides by 3/160
t^3/2 = 23000* 3/160
t^3/2 = 69000/160
t^3/2 = 431.25
t^(3/2 * 2/3) = 431.25^2/3
t = 57.080277
t = 57 days (approx.)
Michael exercises more than 35 minutes per day.
Use t to represent Michael's amount of exercise (in minutes per day).
Answer:
t>35
Step-by-step explanation:
Since Michael exercises more than 35 days, t is greater than 35. To express that in an inequality, the answer is t>35. Hope this helped!
If b^2 = 25 then b= Answer it please
Answer:
b = 5
mark me as brainliest plz!! :DD
Which ordered pair, if included in this relation, would cause it to no
longer be a function?
Answer:
(-6,3)
Step-by-step explanation:
Can someone please help?
Answer:
<IJL and <IJG
Step-by-step explanation:
<IJL and <IJG
-4 (2x + 13) + 3x = 80
How do you solve this out and get the answer
Answer:
-132/5
Step-by-step explanation:
-4(2x+13) + 3x = 80
-8x - 52 + 3x = 80
-5x = 80+52
5x = -132
x = -132/5
Feel free to mark this as brainliest! :D
If it takes 930 kg of food to feed a pair
of elephants for 3 days, how much food
would you need to feed them for a week?
Answer:
2170
Step-by-step explanation:
930 divided be 3= 310
310 multiplied by 7=2170
The distance between Point P and Point Q was 3600 m. Beng Leong started jogging
at 08 35 from Point P and reached Point Q at 08 50. At the same time, Sam started
jogging from Point P at a speed of 200 m/min. Who jogged at a faster speed?
How much faster was his speed?
Answer:
Ben ran at a speed of 240m/min and Sam ran at a speed of 200m/min So Ben is faster by a rate of 40/min
Step-by-step explanation:
Ben's miles per minutes
[tex] \frac{3600}{15} = 240[/tex]
Sam's miles per minute
Given
You measure the period of a mass oscillating on a vertical spring ten times as follows:
Period (s): 1.06, 1.31, 1.28, 0.99, 1.48, 1.37, 0.98, 1.31, 1.59, 1.55
Required:
What are the mean and (sample) standard deviation?
a. Mean: 1.228, Standard Deviation: 0.2135
b. Mean: 1.325, Standard Deviation: 0.1674
c. Mean: 1.292. Standard Deviation: 0.2211
d. Mean: 1.228, Standard Deviation: 0.2098
e. Mean: 1.292, Standard Deviation: 0.2135
Answer:
Step-by-step explanation:
Mean is the ratio of sum of the dataset to the sample size. Mathematically:
[tex]\overline x = \frac{\sum Xi}{N}[/tex]
Xi are the individual periods
N is the sample size
[tex]\sum Xi = 1.06+1.31+1.28+0.99+1.48+1.37+0.98+1.31+1.59+1.55\\\sum Xi = 12.92[/tex]
N = 10
Substitute
[tex]\overline x = \frac{12.92}{10}\\\overline x = 1.292[/tex]
hence the mean of the samples is 1.292
For the standard deviation:
[tex]\sigma = \sqrt{\frac{\sum (x-\overline x)^2}{N} } \\[/tex]
[tex]\sum (x-\overline x)^2 = (1.06-1.292)^2+ (1.31-1.292)^2+ (1.28-1.292)^2+ (10.99-1.292)^2+ (1.48-1.292)^2+ (1.37-1.292)^2+ (0.98-1.292)^2+ (1.31-1.292)^2+ (1.59-1.292)^2+ (1.55-1.292)^2\\\sum (x-\overline x)^2 = 0.43996[/tex]
Substitute into the formula:
[tex]\sigma = \sqrt{\frac{0.43996}{10} }} \\\sigma = \sqrt{{0.043996}}} \\\sigma = 0.2098[/tex]
Hence the standard deviation is 0.2098
PLEASE HELP I AM STUCK
12,049=-58,642+y
Answer:
70,691
Step-by-step explanation:
estimate the answer for 1 2/3 x 5 1/10 (type a whole number
Answer:
Exact Form:
17/2
Decimal Form:
8.5
Mixed Number Form:
8 1/2
Translate the sentence into an equation.
Seven times the sum of a number and 2 is 6.
Use the variable y for the unknown number.
Answer:
7(y+2)=6
Step-by-step explanation:
its right
A circle is inscribed in a square. If the perimeter of the square is 40, what is the area of the circle? Use 3.14 for pi.
Answer:
78.5
Step-by-step explanation:
We have the perimeter of the square, which is 40, and 40/4=10. In this picture, we see that the circle's diameter is the same as the length of one side of the square. Therefore, the diameter of the circle is 10. The are formula for circles is [tex]\pi r^{2}[/tex], where [tex]r[/tex] is the radius. The radius of the circle is just the diameter divided by 2, and 10/2=5. Now, [tex]5^2[/tex] is 25, and [tex]3.14\cdot25=78.5[/tex].
anyone in flvs? we should find each other in live lessons lol
Answer:
nope
Step-by-step explanation:
If a roof has a pitch of 5 to 11, how high will the roof rise over a 33-foot run?
a.
3
C.
2
72 feet
1 feet
b. 15 feet
d.
20 feet
The answer is b. 15ft
SOMEONE PLEASE HELP ILL GIVE BRAINLIEST
Answer:
A.
Step-by-step explanation:
QUICK
solve this equation
a^n+b^n=
Number 10 plzz???????
your job requires that you work at least 40 hours a week you have already worked 15 and there are 4 more days left in the week how many hours do you have to work each day to get at least 40 hours: inequality and solution
Answer:
6.25 hours
Step-by-step explanation:
this is rather simple really,
first, you have to work 40 hours a week
you have already worked 15 so now you can subtract that
40-15= 25hrs
if you have 4 more days of the week you divide the remaining hours by the days left
25/4= 6.25hrs
that would be the bare minimum of hours for you to work a 40 hour week.
7th grade math help me plzzzz
Answer:
a. -14
b. -13
c. -5
d. -3
e. -12
f. 0
Step-by-step explanation:
hope it helps
Answer:
A is -14.
B is -13
C is -5
D is -3
E is -12
F is 0
Step-by-step explanation:
A, B, E both numbers are negative so you just add them together and add a negative sign.
C would read 4-9
D 10-7 and add a - to the answer
F is 6-6
What is the first step when solving the equation 3(3x-5x)+2=-8
Answer:
Collect the like terms
Step-by-step explanation:
(3x-5x)
3x (-2x) + 2 = -8
Your teacher invented another game: You will pick one card from a deck of cards. If
you pick a heart, you will win $25.00. Otherwise, you will lose $5.00.
From the standpoint of the player, what is the expected value of this game?
Enter expected value
What does the expected value tell us about the game?
O The game is good to play, you will make money on average.
O The game is NOT good to play, you will tend to lose money.
O It doesn't matter if you play, you will generally break even.
Answer:
C
Step-by-step explanation:
A gallon of gas costs an average of two dollars is Betty spends $144 a month on gas determine how many gallons of gas she uses a month
Answer:
she uses 72 gallons
Step-by-step explanation:
just do 144/2 and the answer is 72
if you wanna check your answer just do 72x2 and it equals 144
Which expression is the coefficient of the n term -1
Answer:
C. -2n² - n + 5
Step-by-step explanation:
In expression C, the coefficient of the n term is -1;
The expression in choice C is given as:
-2n² - n + 5
The coefficient is the number before a variable;
For n², the coefficient is -2
for n, the coefficient is -1
Which equation shows y=3x−15 in standard form?
A. 15x−5y=1
B. 15x+5y=−1
C. 5x−15y=1
D. 5x−15y=−1
Answer:
c 5x -15y =1
Step-by-step explanation:
5x-15y=1
-5x -15y= 1 -5x change the signs on both sides of the equation
15y = -1 +5x divide both sides by 15
y = -1/15 + 1/3 x Reorder the terms
y = 3x-15
:)
All options are wrong here.
Given equation is [tex]y=3x-15[/tex].
the equation given here is in form of [tex]y=mx+c[/tex] . The general equation of any straight line where m is the gradient of the line (how steep the line is) and c is the y -intercept (the point in which the line crosses the y -axis) .
We have to write [tex]y=3x-15 \\[/tex] in standard form.
The standard form for linear equations in two variables is Ax+By=C.
Now we convert [tex]y=3x-15[/tex] in standard form.
Here [tex]y=3x-15\\[/tex]
[tex]y-3x=-15\\\\-y+3x=15[/tex]
[tex]3x-y=15[/tex]
But no options match with the above standard form of equation.
Hence all options are wrong here.
For more details on standard form for linear equations follow the link:
https://brainly.com/question/7380540
the half life of c14 is 5730 years. Suppose that wood found at an archeological excavation site contains about 35% as much C14 as does living plant material. Determine when the wood was cut
Answer:
The wood was cut approximately 8679 years ago.
Step-by-step explanation:
At first we assume that examination occured in 2020. The decay of radioactive isotopes are represented by the following ordinary differential equation:
[tex]\frac{dm}{dt} = -\frac{m}{\tau}[/tex] (Eq. 1)
Where:
[tex]\frac{dm}{dt}[/tex] - First derivative of mass in time, measured in miligrams per year.
[tex]\tau[/tex] - Time constant, measured in years.
[tex]m[/tex] - Mass of the radioactive isotope, measured in miligrams.
Now we obtain the solution of this differential equation:
[tex]\int {\frac{dm}{m} } = -\frac{1}{\tau}\int dt[/tex]
[tex]\ln m = -\frac{1}{\tau} + C[/tex]
[tex]m(t) = m_{o}\cdot e^{-\frac{t}{\tau} }[/tex] (Eq. 2)
Where:
[tex]m_{o}[/tex] - Initial mass of isotope, measured in miligrams.
[tex]t[/tex] - Time, measured in years.
And time is cleared within the equation:
[tex]t = -\tau \cdot \ln \left[\frac{m(t)}{m_{o}} \right][/tex]
Then, time constant can be found as a function of half-life:
[tex]\tau = \frac{t_{1/2}}{\ln 2}[/tex] (Eq. 3)
If we know that [tex]t_{1/2} = 5730\,yr[/tex] and [tex]\frac{m(t)}{m_{o}} = 0.35[/tex], then:
[tex]\tau = \frac{5730\,yr}{\ln 2}[/tex]
[tex]\tau \approx 8266.643\,yr[/tex]
[tex]t = -(8266.643\,yr)\cdot \ln 0.35[/tex]
[tex]t \approx 8678.505\,yr[/tex]
The wood was cut approximately 8679 years ago.
You have 8 donuts and you want to give 1/4 of them to a friend. How many donuts would your friend get?
Answer: pretty sure the friend would get 2 donuts
Step-by-step explanation:
8 tomatoes for $2 unit rate
I don't have much so please 17
In a certain state's lottery, 45 balls numbered 1 through 45 are placed in a machine and eight of them are drawn at random. If the eight numbers drawn match the numbers that a player had chosen, the player wins $1,000,000. In this lottery, the order in which the numbers are drawn does not matter.
Compute the probability that you win the million-dollar prize if you purchase a single lottery ticket. Write your answer as a reduced fraction.
P
(win) =
A single lottery ticket costs $2. Compute the Expected Value, to the state, if 10,000 lottery tickets are sold. Round your answer to the nearest dollar.
Answer: $
A single lottery ticket costs $2. Compute the Expected Value, to you, if you purchase 10,000 lottery tickets. Round your answer to the nearest dollar.
Answer: $
Step-by-step explanation:
The order of the numbers doesn't matter, so we'll use combinations instead of permutations. The number of combinations is:
₄₅C₈ = 215,553,195
So the probability of a ticket having the winning combination is 1 / 215,553,195.
The expected value to the state is:
E(X) = 10,000 (1) ($2) + 10,000 (1 / 215,553,195) (-$1,000,000)
E(X) = $19954
The expected value to you is:
E(X) = 10,000 (1) (-$2) + 10,000 (1 / 215,553,195) ($1,000,000)
E(X) = -$19954
Write an equation in the line in slope intercept form
Answer:
Y=2x-1
Step-by-step explanation:
In order to find the slope, its rise over run. So you would move from (0,-1) to the next point it intercepts, (1,1) and find it from there
As for the Y-Intercept, it would just be wherever the line connects with the Y axis, which happens to be (0,-1) or Negative 1.