given the function f(x)=-2x^4-16x^3-36x^2, determine all intervals on which f is both decreasing and concave down

Answers

Answer 1

Answer:

(0, ∞)

Step-by-step explanation:

The only maximum, local or otherwise, is at x=0. Since the leading coefficient is negative, the function is decreasing and concave down for x-values greater than 0.

0 < x < ∞ . . . . . decreasing and concave down

Since the leading coefficient of this even-degree function is negative, it will have a generally ∩ shape. It will be decreasing to the right of any local maximum.

The first derivative is negative only for x > 0, so that is the only region where the function is decreasing. Since that x=0 is a local maximum, the function must be concave downward in that neighborhood.

The attached graph shows the function and its first and second derivatives. The function is concave down where the second derivative is negative, to the right of the right-most point of inflection.

_____

Additional comment

A graphing calculator provides a quick answer to a question like this. You can find the same answer algebraically.

The first derivative is ...

f'(x) = -8x^3 -48x^2 -72x = -8x(x^2 +6x +9) = -8x(x+3)^2

This has a zero at x=-3 where the graph of it touches the x-axis, but does not change sign. That means f(x) has a flat spot at x=-3, but is not decreasing except to the right of x=0.

The second derivative is ...

f''(x) = -24x^2 -96x -72 = -24(x^2 +4x +3) = -24(x +1)(x +3)

The second derivative will be negative for x < -3 and x > -1, to the left and right of the points of inflection. This means f(x) is concave upward only for -3 < x < -1, and concave downward everywhere else.

The function is concave downward and decreasing for x > 0.

Related Questions

Plz need help

What is the value of (2/3)

Answers

Answer:

2/9

Step-by-step explanation:

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

2(4/9)-8/3+2

8/9-8/3+2

-16/9+2

2/9

If f(x) = 2x - 1 and g(x) = x^2 - 3x - 2, find (f + g)(x).

Answers

Answer:

SEE attched pic

Step-by-step explanation:

Download symbolab

A recent study revealed the typical American coffee drinker consumes an average of 3.1 cups per day. A sample of 12 senior citizens revealed they consumed the following amounts of coffee, reported in cups, yesterday.
3.1, 3.3 ,3.5 ,2.6, 2.6, 4.3, 4.4 ,3.8 ,3.1 ,4.1 ,3.1, 3.2
(a) State the null hypothesis and the alternate hypothesis. (Round your answers to 1 decimal place.)
(b) State the decision rule for 0.05 significance level. (Negative amounts should be indicated by a minus sign. Round your answers to 3 decimal places.)
(c) Compute the value of the test statistic. (Round your answer to 3 decimal places.)
(d) Do these sample data suggest there is a difference between the national average and the sample mean of the senior citizens?

Answers

Using the t-distribution, it is found that:

The null hypothesis is [tex]H_0: \mu = 3.1[/tex]

The alternative hypothesis is [tex]H_1: \mu \neq 3.1[/tex]

|t| < 2.201: Do not reject the null hypothesis.|t| > 2.201: Reject the null hypothesis.

c) t = 1.853

d) Since |t| = 1.853 < 2.2, we do not reject the null hypothesis, that is, the sample data does not suggest that there is a difference between the national average and the sample mean of the senior citizens.

Item a:

At the null hypothesis, it is tested if the estimate of 3.1 cups per day is correct, that is:

[tex]H_0: \mu = 3.1[/tex]

At the alternative hypothesis, it is tested if the estimate is not correct, that is:

[tex]H_1: \mu \neq 3.1[/tex]

Item b:

This is a two-tailed test, as we are testing if the mean is different of a value, with 12 - 1 = 11 df and a significance level of 0.05, hence, the critical value is [tex]t^{\ast} = 2.2[/tex].

Then, the decision rule is:

|t| < 2.201: Do not reject the null hypothesis.|t| > 2.201: Reject the null hypothesis.

Item c:

We can find the standard deviation for the sample, hence, the t-distribution is used.

The test statistic is given by:

[tex]t = \frac{\overline{x} - \mu}{\frac{s}{\sqrt{n}}}[/tex]

The parameters are:

[tex]\overline{x}[/tex] is the sample mean. [tex]\mu[/tex] is the value tested at the null hypothesis. s is the standard deviation of the sample. n is the sample size.

The values of the parameters, with the help of a calculator for the sample mean and standard deviation, are given by: [tex]\overline{x} = 3.425, \mu = 3.1, s = 0.6077, n = 12[/tex]

Hence, the value of the test statistic is:

[tex]t = \frac{\overline{x} - \mu}{\frac{s}{\sqrt{n}}}[/tex]

[tex]t = \frac{3.425 - 3.1}{\frac{0.6077}{\sqrt{12}}}[/tex]

[tex]t = 1.853[/tex]

Item d:

Since |t| = 1.853 < 2.2, we do not reject the null hypothesis, that is, the sample data does not suggest that there is a difference between the national average and the sample mean of the senior citizens.

A similar problem is given at https://brainly.com/question/24826023

On average, a squirrel lives to be 6.5 years old. The lifespan of a squirrel may
vary by as much as 1.5 years. What is the range of ages that a squirrel lives?

Answers

Answer:

5-8

Step-by-step explanation:

6.5-1.5 = 5

6.5+1.5= 8

URGENT!!! THANK YOU!!!!!

Answers

Answer:

101,100

280

Here's your answer

Helpppp me please omg

Answers

the first graph looks right

please help me quick

Answers

Answer:

D) The answer is AB and HG

Step-by-step explanation:

sides that are equal:

AD=EH

DC=EF

BC=FG

AB=HG

A. Decide whether the given examples illustrate a constant or a variable.
1. Number of family members in each house
2. Amount of money in the bank every month
3. Number of seconds in a minute
4. Weekly expenses of groceries
5. Number of years in a millennium.
Asynchronous task on introduction to algebraic expressions
B. Make your own algebraic expressions based on the given conditions.
1. A variable
2. A combination of any number and any variable related by exponentiation.
3. A combination of any two variables related by subtraction.
4. A combination of any number and any three variables related by multiplication.

pls answer and help me..

Answers

Answer:

a constant is a data item whose value cannot change during the program execution just as its name implies that the value is constant a variable is a data item whose value can change during the program's execution . Thus as its name implies the the value can vary

Write the slope-intercept form of the equation of the line.

Answers

The slope- intercept of the line is y= x + 2. This is because for every time you go up or “rise” 1 unit you move to the right or “run” 1 unit. Therefore, 1/1 is just 1 so we can just leave this as x, however 1x would still work. Also, the line first touches the y-axis when x is 0 and y is 2. Therefore, the slope intercept is 2. So the slope intercept form of this line is still y = x + 2.

(-5,-2),(-7,r) if m=5/9 what is r? slope

Answers

Answer:

r = -28/9

Step-by-step explanation:

use slope formula of (y₂-y₁) / (x₂-x₁)

5/9 = [r - (-2)] / [-7 - (-5)]

5/9 = (r+2) /-2

cross-multiply to get:

-2(5) = 9(r+2)

-10 = 9r + 18

-28 = 9r

r = -28/9

-9/12-(-1/3) A 8/9. B. -8/9. C 5/12 D -5/12

Answers

Answer:

-5/12/ D

Step-by-step explanation:

-9/12 -(-1/3)

turn 1/3 into a fraction with a similar denominator

-9/12-(-4/12)

-(- = addition (+)

-9+4= -5

-5/12

can anyone please help

Answers

Answer:

Adult tickets = $73.5

Child tickets = $20.5

Step-by-step explanation:

[tex]{ \rm{3x + 5y = 50 - - - \{eqn \: 1 \}}} \\ { \rm{x + 5y = 31 - - - \{eqn \: 2 \}}} \\ [/tex]

• Subtract eqn 2 from eqn 1:

[tex]{ \rm{2x = 21}} \\ { \rm{x = 10.5}}[/tex]

[tex]{ \rm{10.5 + 5y = 31}} \\ { \rm{5y = 20.5}} \\ { \rm{y = 4.1}}[/tex]

Marcus is it mixing blue and yellow paint in the ratio of 2 to 3 to make green paint. He wants to make 45 L of green paint. Him being to make a table to help him think about the problem but is unsure of what to do next. Marks find Amandas also mixing paint she wants to make purple paint by mixing 2 cups of blue with a4 cups are red paint. Amanda makes her pain in his left with 48 cups of purple paint how many more cups of purple paint did she use than blue paint? If Amanda has 15 cups of blue paint how many cups repair does she need? Amanda wants her purple paint mixture from part bead to be a little lighter so she mixes in two more cups of white paint what is the ratio of blue paint to repaint the white paint that she used?

Answers

This question is based on the concept of ratio. Therefore, he needs to have 18 liters of blue paint and 27 liters of yellow paint to make 45 liters of green paint.

Given:

Mark was mixing blue and yellow paint ratio of 2:3.

He wants to make 45 liters of green paint.

According to the question,

Blue : Yellow = Green

2 : 3 : 2+3 (Given)

2 : 3 : 5

Therefore, he wants to make 45 liters of green paint.

So, 5 parts = 45 liters

Now, calculating for each part.

We get,

Each part = 45÷ 5 = 9 liters

Now for 2 parts = 9 x 2 = 18 liters

What is the solution to this quadratic equation

Answers

The answer is: B, C, and E

(0,12)
(2,0)
(6,0)

Will mark brainliest

Answers

Answer:

h(x) = 7x - 3

Step-by-step explanation:

f(x) = 4x − 1 and g(x) = −3x + 2

h(x) = f(x) - g(x)

h(x) = 4x - 1 - (-3x + 2)

h(x) = 4x - 1 + 3x - 2

h(x) = 7x - 3

A line passes through (3, 7) and (6, 9). Which equation best represents the line? (4 points) y = 3 over 2 x + 5 y = 2 over 3 x + 5 y = 3x + 2 y = 2 over 3 x + 2

Answers

Given two points, the equation of the line may be determined by,

y - y1 = ((y2 - y1) / (x2 - x1))(x - x1)

Substituting the given values,

y - 7 = ((9 - 7) / (6 - 3))(x - 3)

Simplification will yield to an answer of,

y = 2x/3 +5

Therefore, the answer is the second choice.

How many solutions does the system of equations below have?
4x + 10y = –7
–3x + 9y = –14
No solution
One solution
Infinitely solutions

Answers

Answer:

There is one solution to this system of equations

Step-by-step explanation:

When solving, there is a specific point of intersection which is (7/6,-7/6), making the answer one solution.

I need help showing work

Answers

Answer:

yawa ka ah diyan module tae yan hahaha

don't know sorry mate

ANYBODY HELP. EXPERTS HELP!!!!!!!!!!

Answers

Answer:

Question 1 Between 3 - 4 hrs

Question 2 Between 1 - 3 hrs

Question 3 Between 4 - 8 hrs

Question 4 Between 2 - 3 hrs

Question 5 Represents the starting position

Step-by-step explanation:

Sara is saving up to purchase a small T.V.
She has saved $80, which is 64% of the total
cost of the television. How much does the
television cost?

Answers

Answer:

You got this just keep trying

Step-by-step explanation:

Answer:

It might be 80

Step-by-step explanation:

first you put 64% and $80 as a fraction. 64%/$80. Then next to the fraction, you put x/100. Then you cross multiply. 64 times 100 is 6400. 6400 divided by 80 is 80. Therefore, the answer is 80. Hope this helps!

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