S 2. Let f(x) = x - k√x
a. Find a value of k such that the function has a critical point at x = 25.
b. Is the above critical point a local maximum, local minimum or neither? Show calculus to support your answer.​

Answers

Answer 1

a. A critical point at x = 25 would mean f'(25) = 0 or doesn't exist. We have derivative

[tex]f(x) = x - k \sqrt x \implies f'(x) = 1 - \dfrac k{2\sqrt x}[/tex]

so that

[tex]f'(25) = 1 - \dfrac k{2\sqrt{25}} = 1 - \dfrac k{10} = 0 \implies \boxed{k=10}[/tex]

b. Taking the second derivative, we get

[tex]f''(x) = \dfrac k{4 x^{3/2}} = \dfrac5{2 x^{3/2}}[/tex]

At x = 25, the second derivative has a positive sign,

[tex]f''(25) = \dfrac 5{2 \times 25^{3/2}} = \dfrac 5{2\times5^3} = \dfrac1{50} > 0[/tex]

which means f(x) is concave upward around x = 25, so this critical point is a local minimum.


Related Questions

Solve the quadratic equations by completing the square.
x^2-4x=-1

Answers

Answer:

2 ± √3

Step-by-step explanation:

Solving quadratic equation by completing squares:  

           x² - 4x = -1

Divide the coefficient of x by 2.

                 4 ÷ 2 = 2

 Now, square the result and add that to both sides of the equation.

          2² = 2* 2 = 4

          x² - 4x + 4 = -1 + 4

          x² - 4x + 4 = 3

         x² - 2 * x * 2 + 2² = 3

    Compare it with a² - 2ab + b² . Now , a = x and b = 2

            (x - 2)² = 3

    Take square root both sides

             x - 2 = ±√3

                    x = 2 ± √3

Solutions: x = 2 +√3   ;  2 - √3

A spinner is divided into 12 equal sectors labeled with the letters A through L The spinner is spun 80 times.
How many times is it expected that a vowel will be spun?
——
A.) approximately 20 times
B.) approximately 25 times
C.) approximately 36 times
D.) approximately 40 times

Answers

Answer:

c

Step-by-step explanation:

the answer to this quistion is becasue 36 is an propile number

5 yrs ago, Nuri was thrice as old as Sonu. 10 yrs later, Nuri will be twice as old Sonu. How old are Nuri n Sonu?​

Answers

Answer:

Answer will be 50

Step-by-step explanation:

Let us suppose, present age of Nuri be ‘x’ years and present age of Sonu be ‘y’ years.

Now, it is given that five years ago, Nuri was thrice old as Sonu. Hence,

Five years ago,

Nuri’s age = x-5 years

Sonu’s age = y-5 years

And relation between ages can be given as

Nuri’s age = 3×sonu’s age or

x-5 = 3(y-5)

x-5 = 3y-15

x-3y+10 = 0 ………..(i)

Another relation is given in the problem that ten years later, Nuri is twice as old as Sonu.

So, ten years ago,

Nuri’s Age = x+10

Sonu’s Age = y+10

And relation between ages can be written as

x+10 = 2(y+10)

x+10 = 2y+20

x-2y-10 = 0 …………..(ii)

Now we can solve the equation (i) and (ii) to get values of x and ‘y’ or present ages of Nuri and Sonu.

Value of ‘x’ from equation (i) be

x = 3y-10 ……….(iii)

Putting value of ‘x’ from equation (iii) in equation (ii) we get,

3y-10-2y-10 = 0

y = 20

Now, from equation (iii) value of ’x’ can be given as,

x= 3(20)-10

x = 50

Hence, the present ages of Nuri and Sonu are 50 years and 20 years respectively.

Assume the random variable X has a binomial distribution with the given probability of obtaining a success. Find the following probability, given the number of trials and the probability of obtaining a success. Round your answer to four decimal places.

P(X=14), n=15, p=0.8

Answers

Use the PMF for the given distribution:

[tex]P(X=x) = \begin{cases}\dbinom{15}x 0.8^x (1-0.8)^{15-x} & \text{if } x \in\{0, 1, 2, \ldots, 15\} \\ 0 & \text{otherwise}\end{cases}[/tex]

Then the probability that X = 14 is

[tex]P(X=14) = \dbinom{15}{14} 0.8^{14} 0.2^1 \approx \boxed{0.1319}[/tex]

Convert (728), to base 10​

Answers

Answer:

2D8

Step-by-step explanation:

To convert decimal number 728 to hexadecimal, follow these steps:

step 1 =Divide 728 by 16 keeping notice of the quotient and the remainder.

step 2 =Continue dividing the quotient by 16 until you get a quotient of zero.

step 3 =Then just write out the remainders in the reverse order to get hexadecimal equivalent of decimal number 728.

Using the above steps, here is the work involved in the solution for converting 728 to hexadecimal number:

728 / 16 = 45 with remainder 8

45 / 16 = 2 with remainder 13 (D)

2 / 16 = 0 with remainder 2

Then just write down the remainders in the reverse order to get the answer, The decimal number 728 converted to hexadecimal is therefore equal to :

2D8

ASAP!!!
Alicia found $1.90 on the beach. Her brother found three times as much money. How much money did Alicia and her brother find in total?
Please be accurate!

Answers

Answer: The correct answer is $7.60.

Step-by-step explanation: First, you multiply 1.90 and 3. This gives you 5.7. Then, you add 1.9. This gives you $7.60.

Answer:

£7.60

Step-by-step explanation:

Alicia found £1.90, we can give this the value x

Her brother found triple the amount, or 3x

In total they found 4x

If £1.90 is x, 4x is £7.60

8.92 x 10^6 in scientific notation

Answers

Answer:

8.92 * 10^10

Step-by-step explanation:

1. Convert to decimal notation

[tex]8.92*10^6[/tex]

The exponent is 6, making it 10 to the power of 6. As the exponent is positive, the solution is a number greater than the origin or base number. To find our answer, we move the decimal to the right 6 time(s):

8.92 -> [tex]8920000[/tex]

2. Final result

[tex]8920000[/tex]

Move the decimal so there is one non-zero digit to the left of the decimal point. The number of decimal places you move will be the exponent on the 10.  If the decimal is being moved to the right, the exponent will be negative. If the decimal is being moved to the left, the exponent will be positive.

8.92 * 10^10

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

Why learn this

Scientific notation, or standard form, makes things easier when working with very small or very big numbers, both of which come up frequently in the fields of science and engineering. It is used in science, for example, to convey the mass of the heavenly bodies: Jupiter’s mass is [tex]1.898*10^{27}[/tex]kg, which is easier to comprehend than writing the number 1,898 followed by 24 zeroes. Scientific notation also makes solving problems that use such high or low numbers more straightforward.

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

Terms and topicsScientific Notation

Scientific notation is also referred to as scientific form or standard index form, or in the UK, standard form.

Adult tickets to a basketball game cost $5. Student tickets cost $1. A total of $3,128 was collected on the sale of 1,336 tickets. How many of each type of ticket were sold?

Answers

Answer:

Adults = 448

Students = 888

Step-by-step explanation:

Write equations with info given

A = Adult tickets

S = Student tickets

5A+1S=3,128

A+S=1336

Subtract equations from each other

4A=1792

Solve for A

A=448

Plug A into second equitation

448+S=1336

Solve for S

S=888

What is k equal to if StartFraction 7.6 over 2 EndFraction = StartFraction 9.5 over k EndFraction?
1.6
2.5
3.8
4.8

Answers

2.5 is the answer! trust to this! :) 2.5

13. Figure QRSP is a rectangle.
Q.
100°
What is the measure of angle RPS?
A. 40 degrees
C. 80 degrees
B. 50 degrees]

Answers

Answer:

b 50 degrees bavaggagshdd

I need the answer for this question please

Answers

The sum of √30 + √50 lies between 12 and 13.

What is the sum of the numbers?

The square root of a number can be described as number that when multiplied with itself yields that number.

√30 = 5.48

√50 = 7.07

5.48 + 7.07 = 12.55

The consecutive integers are 12 and 13

To learn more about how to calculate square root, please check: https://brainly.com/question/8085738

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ZA=C
Round your answer to the nearest hundredth.
C
B
6
8
A
?

Answers

Answer:

? = 41.41°

Step-by-step explanation:

The known side length is adjacent to the angle we need to find hence we will use cosine

cosx = adjacent /hypotenuse

cos(?) = 6 / 8

simplify fraction, cos(?) = 3 / 4

? = arccos(3 / 4)

Please Answer Fast

Find the length of the hypotenuse.

Answers

Answer:

c2= 55

Step-by-step explanation:

c2=a2+b2

=33^+44^

= 3025

or,c2=(55)2

:c=55

Answer:

H = 55

Step-by-step explanation:

Base = 33Hypotenuse = ?Altitude = 44

Applying Pythagoras' theorem,we obtain

(H)² = (B)²+(A)²(H)² = (33)² + (44)²(H)² = 1089 + 1936(H)² = 3025(H) = √(3025)H = √(55*55)H = 55

Hence,the length of hypotenuse is 55.

In algebra, there are lots of rules and properties to remember. The good news is that once you understand them, you can apply them in lots of different orders and combinations. Give an example of a mathematic problem that can be solved in multiple ways by applying properties of algebra differently. Explain your reasoning.

Answers

Algebraic properties can be applied in any mathematical equation.

How to explain the algebraic property?

There are several algebraic properties; they include:

Distributive propertyAdditive propertyInverse propertyCommutative propertyAnd so on

All these properties can be applied in a mathematical equation.

An instance is as follows:

3(x + 2) = 18

Method 1

Apply the distributive property

3x + 6 = 18

Apply the subtraction property of equality

3x = 12

Apply the division property of equality

x = 4

Method 2

Apply the division property of equality

x + 2 = 6

Apply the subtraction property of equality

x = 4

Read more about mathematical properties at:

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1
2
3
4
5
6
7
8
9 10
What is the value of x in the equation xy = 30, when y = 15?
•4
•8
•80
•200

Answers

Answer:

xy=30, when y is 15 by substitute 15 in place of y then dividing both side by 15 we get x=2

Finding the relationship of two lines

Answers

[tex]Explanation[/tex]

This is very basic all you have to look at is the 2x because whenever the number has a variable with [tex]x[/tex] it means its the slope and the slope will tell you whether they are parallel or perpendicular.

so as you can see the slopes are alike because they are both 2x

Thus, the answer is Parallel

//-carry on learning-//

1. Solve the quadratic function by graphing. x²-3x - 18 - 0​

Answers

Answer:

that's easy all you have to do is find out what is the value of x then divided by 2 once you divide by 2 subtract 3x 18 and 0

Solve for x to the nearest tenth.
Can someone help me?​ Multi-Step Diagrams

Answers

Answer:

Step-by-step explanation:

Change 0.45° to equivalent minutes and seconds. Round to the nearest second if necessary.

Answers

0.45° in minutes is 27.36 minutes and in seconds is 21.6 seconds.

Why is it necessary to divide decimal degrees by 60 to obtain minutes and seconds?

In a complete rotation, circles and spheres have 360 degrees. One degree is divided into sixty minutes, and one minute is divided into sixty seconds. You may see that your measurement is 91 full degrees plus 0.456 of a degree if you have 91.456 degrees.

How 0.45° is converted to equal minutes and seconds?

To convert 0.456 degrees to minutes, multiply 0.456*60 and you will get the answer as 27.36 minutes. You now have a total of 27 minutes and 0.36 of a minute.To express 0.36 minutes seconds in decimal form, multiply 0.36*60 to get 21.6 seconds. You can round up to twenty two seconds because your decimal 0.6 is bigger than 0.5.

To learn more about minutes and seconds conversion, refer

https://brainly.com/question/2144524

Is 12/19 rational or irrational?

Answers

Answer:

irrational

Step-by-step explanation:

Pls help meeeeeeeeeeeee

Answers

Answer:

24%

Step-by-step explanation:

there are 50 numbers total

number of 4's: 7
number of 7's: 5

it's asking for the odds of a 4 or a 7 meaning that they're fine with either one. that means you can ADD the number of them up!

7 + 5 = 12

to get the odds, we need to divide!

12/50 = ?.24

convert that into a percent!

24%

let me know if you're still confused :))

a bicycle wheel has a diameter of 65cm what is the length of one revolution of the wheel PLEASE HELP​

Answers

AnswerAnswerAnswerAnswer: C = πd = 65π = 204.2 cm

Step-by-step explanation: C = pi*d

where d is the diameter.

First we get the circumference, then we multiply it by the number of revolutions, which is 20:

C = 3.14 * 65

C = 204.1 cm (this is only equal to 1 revolution)

Therefore, total distance travelled in after 20 revolutions is

204.1 * 20 = 4082 cm

204.2 is the answer to the question

In a P.7 class, 20% of the boys were absent for the Mock Examinations, of the remainder of the boys were present Find the fraction of the girls in the class.​

Answers

Fine the fraction of the girls class absent examination

Help, and if you can give me a step by step explanation

Answers

Answer:

the first option

Step-by-step explanation:

variability !

what does that word tell us ?

it means that there are more individuals differences.

you could also use "accuracy" as the opposite - we are aiming for the mean value ...

imagine some bow and arrow tournament.

who wins ?

the person with the highest accuracy across all the attempts (and that means the lowest variability in the results across all attempts relatively to the target center representing the predefined mean value).

now look at the graphic for neighborhood A.

and then for neighborhood B.

which one has the data points more clustered around the center (where the mean value is going to be) ? this one has lower variability than the one where the data points are having more than one cluster or are even all over the place.

remember, for the variability you have to add all the differences to the mean value. the smaller the differences to the mean value, the smaller the variability.

in neighborhood B almost all data points have a larger difference to the mean value.

so, the variability will be higher here.

A survey indicated that 4 out of 6 doctors used brand X aspirin. If 3600 doctors were surveyed, how many used brand X?

Answers

Answer: 2,400 doctors used brand X aspirin.

Step-by-step explanation: The question notifies us that 3,600 total doctors were surveyed. This automatically lets us know that 6/6 doctors = 3,600 doctors. We can find the unit rate from this point by dividing 3,600 by 6. We will find that 600 doctors represents 1/6 doctors. We can multiply our unit rate by 4 to find that 4 out of 6 doctors, or 2,400 doctors, use brand X aspirin. 4/6 of 3,600 is 2,400, so 2,400 doctors used brand X aspirin. Hope this helps!

Answer:

1200 doctors

Step-by-step explanation:

60% of doctors use brand X aspirin.

So, what is 60% of 2000?

(0.6) (2000) = 1200

1200 out of the 2000 use brand X.

round your final answer to the nearest degree ​

Answers

Answer:

The correct answer is 37°

A school wants 2 chaperones for every 25 students on a field trip. There are 100 students going on the field trip. How many chaperones does the school need?
A
4

B
8

C
108

D
50

Answers

Using proportions, it is found that the number of chaperones that the school needs is given by:

B. 8.

What is a proportion?

A proportion is a fraction of a total amount, and the measures are related using a rule of three.

In this problem, 2 chaperones are needed for every 25 students. How many are needed for 100 students? The rule of three is given by:

2 chaperones - 25 students

n chaperones - 100 students

Applying cross multiplication:

25n = 2 x 100

n = 200/25

n = 8.

Hence option B is correct.

More can be learned about proportions at https://brainly.com/question/24372153

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Find the area of a regular polygon with 7 sides that has a side length of 6 inches and an apothem of 8 inches.

Area = [?]in2

Answers

Answer:

see the attachment photo!


9 < 5+y
Solve the inequality

Answers

Answer:

4<y

Step-by-step explanation:

1st step:9=5+y

2nd step: 9-5=y

3rd step: 4=y

4th step: 4<y

Answer:

y > 4 or 4 < y

Step-by-step explanation:

In this inequality, the < sign, also known as the less than sign, means that 9 is less than the value of 5 + y. Solving inequalities can be simple to do - let's begin!

9 < 5 + y

We know that we must isolate y to determine its value. We can do this by subtracting 5 from both sides of the < sign.

9 - 5 < 5 + y - 5

Simplify!

4 < y  → This means that 4 is less than y. Let's rewrite this.

y > 4 → Rewritten, your answer looks like this! This now states that y is greater than 4, which is the same as 4 being less than y.

For more information regarding inequalities, be sure to check out the following answers!

https://brainly.com/question/20085191https://brainly.com/question/12556359https://brainly.com/question/12526104

alex has a box of 250 nails. he uses 80 nails. then he loses 35 nails. how many nails does alex have left? what is the hidden question

Answers

The answer is 100+30+5
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