Please help!!!!
Oak wilt is a fungal disease that infects oak trees. Scientists have discovered that a single tree in a small forest is infected with oak wilt. They determined that they can use this exponential model to predict the number of trees in the forest that will be infected after t years.
f(t) = e^0.4t
1. The scientists believe the forest will be seriously damaged when 21 or more of the forest’s 200 oak trees are infected by oat wilt. According to their model, how many years will it take for 21 of the trees to become infected?

Type the correct answer in the box. Use numerals instead of words. Round your answer to the nearest tenth.

2. Rewrite the exponential model as a logarithmic model that calculates the number of years g (x) for the number of infected trees to reach a value of x.

Answers

Answer 1

To solve this question, we need to solve an exponential equation, which we do applying the natural logarithm to both sides of the equation, both to find the needed time and to find the inverse function. From this, we get that:

It will take 7.6 years for 21 of the trees to become infected.The logarithmic model is: [tex]g(x) = \frac{\ln{x}}{0.4}[/tex]

Number of trees infected after t years:

The number of trees infected after t years is given by:

[tex]f(t) = e^{0.4t}[/tex]

Question 1:

We have to find the number of years it takes to have 21 trees infected, that is, t for which:

[tex]f(t) = 21[/tex]

Thus:

[tex]e^{0.4t} = 21[/tex]

To isolate t, we apply the natural logarithm to both sides of the equation, and thus:

[tex]\ln{e^{0.4t}} = \ln{21}[/tex]

[tex]0.4t = \ln{21}[/tex]

[tex]t = \frac{\ln{21}}{0.4}[/tex]

[tex]t = 7.6[/tex]

Thus, it will take 7.6 years for 21 of the trees to become infected.

Question 2:

We have to find the inverse function, that is, first we exchange y and x, then isolate x. So

[tex]f(x) = y = e^{0.4x}[/tex]

[tex]e^{0.4y} = x[/tex]

Again, we apply the natural logarithm to both sides of the equation, so:

[tex]\ln{e^{0.4y}} = \ln{x}[/tex]

[tex]0.4y = \ln{x}[/tex]

[tex]g(x) = \frac{\ln{x}}{0.4}[/tex]

Thus, the logarithmic model is:

[tex]g(x) = \frac{\ln{x}}{0.4}[/tex]

For an example of a problem that uses exponential functions and logarithms, you can take a look at https://brainly.com/question/13812761


Related Questions

(Picture) Could someone help me solve this I need to use Inverse Operations but I don't fully understand? I'll mark brainliest, 10 Points.

Answers

Answer:

[tex]x = - 8[/tex]

Step-by-step explanation:

First,Step write the given equation.

[tex] \frac{x}{2} + 7 = 3[/tex]

In Algebra, we learn how to solve for a missing term called a variable. We must use inverse operations to undo terms to isolate our variable. Inverse operations means that we do the opposite of the given.

Opposite of Addition is Subtraction, vice versa.Opposite of Multipication is Division, vice versa.

For example, say we have a equation

[tex]x + 2 = 3[/tex]

We would subtract 2 from both sides. E.g( remember the golden rule of algebra). What we do to one side, we do the other. This applies when we solving for a variable.

This means that

[tex]x = 1[/tex]

And if we substitute 1 in for x, it is indeed true.

[tex]1 + 2 = 3 = 3[/tex]

Now, back to the question.

[tex] \frac{x}{2} + 7 = 3[/tex]

First, we subtract 7 from both sides to get rid of the 7 on the left side. Also remeber to undo terms that aren't included in the variable when solving these problems.

So now we got

[tex] \frac{x}{2} = - 4[/tex]

Then we multiply 2 by both sides since that the opposite of division.

[tex] \frac{x}{2} \times 2 = x = -4 \times 2 = - 8[/tex]

So this means that

[tex]x = - 8[/tex]

If we plug this in, this is true.

[tex] \frac{ - 8}{2} + 7 = 3[/tex]

find the lenght of the missing side:

Answers

Answer:

x=15.73292

Step-by-step explanation:

Since this is a right triangle, we can use trig functions

cos theta = adj/ hyp

cos 70 = x / 46

46 cos 70 =x

x=15.73292

Answer:

15.73

Step-by-step explanation:

cos(x) = adjacent leg / hypotenuse

cos(70) = x / 46

0.342 = x / 46

0.342 x 46 = x

x = 15.73

What is the constant of proportionality in the equation x 2
—- = ——
Y 9

Answers

Answer:

The Constant is 9/2


Four times an angle is equal to half of its supplement. Find the measures of both angles.

Answers

Answer:

The bigger angle is 144 degrees and the smaller one is 36 degrees

helpppp: write the rule that describes the composition of transformations

Answers

omg i need help on tht too

A retailer bought 1000 glass tumblers at rs 80 each.50 glass tumblers were broken and he sold the rest at Rs 96 each .find his profit or loss percent​

Answers

Step-by-step explanation:

Soln

Given

Cp of 1 glass tumbler=80.1000

=Rs 80000

Number of broken glass tumbler=50

Number of remaining glass tumbler=1000-50

=950

Sp of one glass tumbler=96

Sp of 950 glass tumbler=96.950

=91200

Now

Sp > Cp so it is profit

Profit%=sp-cp/cp.100

=91200-80000/80000.100

=11200/80000.100

=14%

Answer:

14%profit

Step-by-step explanation:

Cost of 1000 tumblers=1000×80=80,000

50 of them were broken: 1000-50=950

: He sells 950 tumblers of rs.96 each= ( 950×96)

S.P=91200

We can clearly see he gains for rs.11200.

P%=gain/C.P×100

11200×80000×100

=14%

An item is regularly priced at $95. It is on sale for 85% off the regular price.

Answers

Answer:

14.25

Step-by-step explanation:

95*0.85=80.75

95-80.75=14.25

Answer:

The sale took $14.25 off the original price, so the item is currently $80.75 with the sale.

Single adults: According to a Pew Research Center analysis of census data, in 2012, 20% of American adults ages 25 and older had never been married. Suppose that we select random samples from this population of American adults ages 25 and older. For each sample we then calculate the proportion that had never been married.

For which of the following sample sizes will the sampling distribution be approximately normal?

Wang, W., and Parker, K. (2014). Record Share of Americans Have Never Been Married. Pew Research Center. http://www.pewsocialtrends.org/2014/09/24/record-share-of-americans-have-never-married/

A) 25
B) 50
C) 75

Answers

Answer:

B. 50

Step-by-step explanation:

Central limit theorem is used to calculate the sampling distribution of the given case. The number of adults who are 25 years of age or above and not married is 20% of the samples selected. The standard deviation is 0.06 while the sample size should be 50 to conclude the results.

Which expression is equivalent to….

Answers

Answer:

the answer is {2^5}

hope it helps :)

(2^1/2×2^3/4)^2

(2^(2/4+3/4))^2

(2^5/4)^2

2^(5/4×2)

2^(5/2)

√2^5

Answered by Gauthmath must click thanks and mark brainliest

1. The product of two consecutive numbers is 42. What are the numbers?

Answers

Answer:

6, 7

Step-by-step explanation:

6 x 7 = 42

6 and 7 are consecutive
6*7=42

Given the function g(x) = x2 + 10x + 18, determine the average rate of change of
the function over the interval -11 < x < -1.

Answers

Answer:

-2.

Step-by-step explanation:

Average rate of change of the function = [ f(-1) - f(-11)] / [(-1 - (-11)]

= [(-1)^2 + 10*-1 + 18 - ((-11)^2 + 10*-11 + 18)] / 10

= (1 - 10 + 18 - (121 - 110 + 18) / 10

= (9 - (29) /10

= -20/10

= -2.

Answer:

Step-by-step explanation:

The answer is +2 or 2.

You flip a coin and roll a six-sided die. What is the
probability of flipping heads and rolling a number greater
than or equal to 5?

Answers

Answer:

The probability of flipping heads is 1/2

The probability of rolling 5 or more is 1/3.

So the total probability is 1/2 x 1/3 , which is 1/6.

Let me know if this helps!

Answer:

1/6

Step-by-step explanation:

The probability of flipping heads is 1/2

The probability of rolling 5 or more is 1/3.

So the total probability is 1/2 x 1/3 , which is 1/6.

PLEASEE HELP ASAP........

Answers

Answer:

(C). 126

Step-by-step explanation:

[tex]\frac{45}{x}[/tex] = [tex]\frac{65}{182}[/tex]

x = 126

Answer:

Hello,

Answer C\\

Step-by-step explanation:

Triangle EUT is similar to triangle EGF

[tex]\dfrac{EU}{EG} =\dfrac{ET}{EF} \\\\\dfrac{140-90}{140} =\dfrac{45}{EF} \\\\\\EF=\dfrac{45*140}{50} \\\\\\RF=126\\\\Answer\ C\\[/tex]

0.4 x 10 =....
1.25 x 10 =
97.465 x10 =​

Answers

Answer:

0.4 × 10 = 4

1.25 × 10 = 12.5

97.465 × 10 = 974.65

The difference of a number and 11

Answers

Answer:

x - 11

Step-by-step explanation:

"A number" is the same thing as a variable.

Answer:

x-11

Step-by-step explanation:

any 5
algebraic formulas

Answers

Answer:

a2 – b2 = (a – b)(a + b)

(a + b)2 = a2 + 2ab + b2

a2 + b2 = (a + b)2 – 2ab

(a – b)2 = a2 – 2ab + b2

(a + b + c)2 = a2 + b2 + c2 + 2ab + 2bc + 2ca

(a – b – c)2 = a2 + b2 + c2 – 2ab + 2bc – 2ca

(a + b)3 = a3 + 3a2b + 3ab2 + b3 ; (a + b)3 = a3 + b3 + 3ab(a + b)

(a – b)3 = a3 – 3a2b + 3ab2 – b3 = a3 – b3 – 3ab(a – b)

a3 – b3 = (a – b)(a2 + ab + b2)

a3 + b3 = (a + b)(a2 – ab + b2)

(a + b)4 = a4 + 4a3b + 6a2b2 + 4ab3 + b4

(a – b)4 = a4 – 4a3b + 6a2b2 – 4ab3 + b4

a4 – b4 = (a – b)(a + b)(a2 + b2)

a5 – b5 = (a – b)(a4 + a3b + a2b2 + ab3 + b4

Answer:

a2 – b2 = (a – b)(a + b)

(a + b)2 = a2 + 2ab + b2

a2 + b2 = (a + b)2 – 2ab

(a – b)2 = a2 – 2ab + b2

(a + b + c)2 = a2 + b2 + c2 + 2ab + 2bc + 2ca

(a – b – c)2 = a2 + b2 + c2 – 2ab + 2bc – 2ca

(a + b)3 = a3 + 3a2b + 3ab2 + b3 ; (a + b)3 = a3 + b3 + 3ab(a + b)

(a – b)3 = a3 – 3a2b + 3ab2 – b3 = a3 – b3 – 3ab(a – b)

a3 – b3 = (a – b)(a2 + ab + b2)

a3 + b3 = (a + b)(a2 – ab + b2)

(a + b)4 = a4 + 4a3b + 6a2b2 + 4ab3 + b4

(a – b)4 = a4 – 4a3b + 6a2b2 – 4ab3 + b4

a4 – b4 = (a – b)(a + b)(a2 + b2)

a5 – b5 = (a – b)(a4 + a3b + a2b2 + ab3 + b4)

What are the amplitude, period, phase shift, and midline of f(x) = 7 cos(2x + π) − 3? (6 points) Amplitude = −3; period: π; phase shift: x = negative pi over 2 ; midline: y = 3 Amplitude: 7; period: π; phase shift: x = negative pi over 2 ; midline: y = −3 Amplitude: 7; period: 2π; phase shift: x = pi over 2 ; midline: y = 3 Amplitude: −3; period: 2π; phase shift: x = pi over 2 ; midline: y = −3

Answers

Answer:

So the amplitude is 7

The period is pi

The phase shift is negative pi/2

The midline is -3

Step-by-step explanation:

A trigonometric function is the same as

[tex]f(x) = a \cos(b(x + c)) - d[/tex]

Where a is the amplitude, 2 pi/ absolute value of b is the period, c is the phase shift, and d is the vertical shift or midline.

Given the function

[tex]7 \cos(2x + \pi) - 3[/tex]

The amplitude is 7, and the midline is -3. The period is

[tex] \frac{2\pi}{2} = \pi[/tex]

The phase shift is

[tex]2x + \pi = 0[/tex]

[tex]2x = - \pi[/tex]

[tex]x = - \frac{\pi}{2} [/tex]

So the amplitude is 7

The period is pi

The phase shift is negative pi/2

The midline is -3.

ayudenme pls aaaaaaaaaaaaaaaaaaaaaaaaaaaa

Answers

Answer:

aslo bien jjjjjjj

Step-by-step explanation:

factorize = n!+(n-1)!

Answers

Answer:

Hello,

Step-by-step explanation:

n! + (n-1)!

=(n-1)! * n+ (n-1)!

=(n-1)! * (n+1)

Samuel takes 5 hours to make a table and a chair. He takes 9 hours to make 3 chairs
and a table. How much time does he take to make a table?

Answers

Answer:

3 hours

Step-by-step explanation:

t = time to make a table

c = time to make a chair

t + c = 5

t+3c = 9

Subtract the second equation from the first

t+3c = 9

-(t + c = 5)

-----------------------

       2c = 4

Divide by 2

2c/2 = 4/2

c =2

2 hours for the chair

t+c = 5

t+2 = 5

t = 5-2

t = 3hours

Answer:

It takes 3 hours to make a table.

Step-by-step explanation:

Table and chair : 5 hours

Table and 3 chairs : 9 hours

(Table and 3 chairs) - (Table and chair) = (2 chairs)

9 hours - 5 hours = 4 hours

2 chairs : 4 hours / 1 chair : 2 hours

Table and chair : 5 hours

Chair : 2 hours

Table: x hours

5 - 2 = 3

Table : 3 hours

Which graph represents the function? f(x)=5√x

Answers

Step-by-step explanation:

Since the x is inside of the square root, the x value must be positive. This makes x {0,infinity). Yet, when square rooting x, you should have both a negative and a positive value for y. So, this should be your graph.

Is 6272 a perfect square? If not find the smallest number by which it must be divided so that the product becomes a perfect square.

Answers

Answer:

(2^7)*(7^2)

Step-by-step explanation:

2*2*2*2*2*2*2*7*7=6272where2 is the smallest number by which it becomes a perfect square

HELPPPPPPPP!!!!!!!!!!!!!!!!!

Answers

1)3
2)5/4
3)1
4)3/2
5)1.3
6)4
7)0
8)1
9)7
10)2

You would like to know how effective a diet program is at helping people lose weight. 18 over-weight people are randomly selected to participate in the program. They are weighed before and after the program and the results are listed below. Do these results give evidence that the diet program is effective at the 1% significance level?

Answers

Answer:

There is not enough evidence to support the claim that drug is effective at 1%

Step-by-step explanation:

For this we use the pored test as we have dependent test;

Difference :

10,5,-5,3,-3,4,2,-3,0,10,8,-2,3,-2,5,5,4,0

Hypothesis :

H0 : μd = 0

H0 : μd ≠ 0

The mean of d, dbar = Σd / n = 44 / 18 = 2.44

The standard deviation, Sd = 4.45 (using calculator)

The test statistic, T : dbar / (Sd/√n)

T = 2.44 / (4.45/√18)

T = 2.44 / 1.0488750

T = 2.326

Degree of freedom, df = n - 1 ; 18 - 1 = 17

The Pvalue = 0.0326

α = 0.01

Since Pvalue < α ; we fail to reject H0

Find the place value of 8 in 2456.1387.
Tenths
Hundredths
Thousandths
Thousands

Answers

Answer: Third Choice. Thousandths

Step-by-step explanation:

Concept:

Here, we need to know the order and name of each place value.

Please refer to the attachment below for the specified names.

Solve:

STEP ONE: Orde and name each place

2 ⇒ One Thousands

4 ⇒ Hundreds

5 ⇒ Tens

6 ⇒ Ones

.

1 ⇒ Tenths

3 ⇒ Hundredths

8 ⇒ One Thousandths

7 ⇒ Ten Thousandths

STEP TWO: Find the number [8] in the number

As we can see from the list above, 8 is at the right of the decimal point, thus, the place value is Thousandths.

Hope this helps!! :)

Please let me know if you have any questions

If 1 angle is four time of another angle in linear pair find the angles. Please do it fast as you can

Answers

Answer:

let the angle be x then other angle is 4x

so,

x + 4x = 180

5x = 180

x = 36

so other angle I.e 4x = 4 × 36 = 144

Let one angle be x

Other angle=4x

Both are linear pair hence their sum will be 180

[tex]\\ \sf \longmapsto x+4x=180[/tex]

[tex]\\ \sf \longmapsto 5x=180[/tex]

[tex]\\ \sf \longmapsto x=\dfrac{180}{5}[/tex]

[tex]\\ \sf \longmapsto x=30[/tex]

[tex]\\ \sf \longmapsto 5x=5(30)=150[/tex]

42 deliveries in 3 hours = deliveries per hour

Answers

Answer:

14 deliveries per hour

Step-by-step explanation:

42/3

14

The person makes 14 deliveries per hour

Answer:

14

Step-by-step explanation:

42 / 3 = 14

cho tứ giác ABCD. Gọi M,N,P,Q là trung điểm của các cạnh AB, CD, AD, BC. Chứng minh rằng vecto MP = vecto QN, vecto MQ = vecto PN

Answers

Answer:

Step-by-step explanation:

Xét tam giác DAB có: P là trung điểm AD, M là trung điểm AB

=> MP là đường trung bình của tam giác DAB => MP//BD và MP=[tex]\frac{1}{2}[/tex]BD  (1)

Xét tam giác DBC có: N là trung điểm DC, Q là trung điểm BC

=> QN là đường trung bình của tam giác DBC => QN//BD và QN=[tex]\frac{1}{2}[/tex]BD  (2)

Từ (1) và (2) => vecto MP song song cùng chiều với vecto QN

và độ dài MP = độ dài QN = [tex]\frac{1}{2}[/tex]BD

=> vecto MP = vecto QN

Tương tự xét các tam giác DAC và tam giác ABC => vecto MQ = vecto PN

name the property that the following statement illustrates 84+8=8+84

Answers

Answer:

the commutative property of addition :)

Find the cross product (7,9, 6)x 44, 1, 5). Is the resulting vector perpendicular to the given vectors?
a. (-57, 43, 33); yes
c. (33. – 59, - 57); no
b. (39, – 59,43), yes
d. (33, - 57, 49); no

Answers

Answer:

Option B, (39, -59, 43)

Answered by GAUTHMATH

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