Calculate the value of k for which the polynomial equation f(x)=x^3-kx+12 has the root of x=-4

Answers

Answer 1

If x = -4 is a root of f(x), then dividing f(x) by x + 4 leaves a remainder of 0.

Compute the quotient,

(x³ - kx + 12) / (x + 4)

x³ = x² • x, and

x² (x + 4) = x³ + 4x²

Subtract this from the dividend (f(x)) to get an initial remainder of

(x³ - kx + 12) - (x³ + 4x²) = -4x² - kx + 12

-4x² = -4x • x, and

-4x (x + 4) = -4x² - 16x

Subtract this from the previous remainder to get a new one of

(-4x² - kx + 12) - (-4x² - 16x) = (16 - k) x + 12

(16 - k) x = (16 - k) • x, and

(16 - k) (x + 4) = (16 - k) x + 64 - 4k

which gives the next remainder,

((16 - k) x + 12) - ((16 - k) x + 64 - 4k) = 4k - 52

4k - 52 does not divide x, so we're done and what we've shown is

f(x) / (x + 4) = x² - 4x + 16 - k + (4k - 52)/(x + 4)

(just gathering the bold terms above and the last remainder)

The remainder should be 0, so that

4k - 52 = 0

4k = 52

k = 13


Related Questions

which equation shows that the pythagorean identity is true for Ø=pi? select the equation that is the form sin^2(pi)+cos^2(pi)=1

a.0^2 +1^2=1
b.0^2 +(-1)^2=1
c. 1^2+0^2=1
d.(-1)^2+0^2=1

Answers

Answer: For This Specific Question it is B, But there is a question very similar that doesn't have the pi's in the equation and the answer to that one is A.

Step-by-step explanation: Very sorry if this is confusing :)

Pythagorean identities are three basic identities for trigonometric ratios. The equation that is of the form [tex]\sin^2(\pi) + \cos^2(\pi) =1[/tex] is given by: Option B: [tex]0^2 + (-1)^2 = 1[/tex]

Equations which shows that the Pythagorean identities are true will be verifying them for some specific angles. For that we need to know about Pythagorean identities.

What are Pythagorean identities?

[tex]sin^2(\theta) + cos^2(\theta) = 1\\\\1 + tan^2(\theta) = sec^2(\theta)\\\\1 + cot^2(\theta) = csc^2(\theta)[/tex]

Using the first Pythagorean Identity to get one of its special case

For angle being [tex]\pi[/tex] radians(or equal to 180 degrees), we have:

[tex]sin(\pi) = 0\\cos(\pi) = -1[/tex]

Thus, for the first Pythagorean identity at angle [tex]\pi[/tex] radians, we get:

[tex]sin^2(\pi) + cos^2(\pi) = 1\\\\0^2 + (-1)^2 = 1[/tex]

Thus, the equation that is of the form [tex]\sin^2(\pi) + \cos^2(\pi) =1[/tex] is given by: Option B: [tex]0^2 + (-1)^2 = 1[/tex]

Learn more about Pythagorean identities here:

https://brainly.com/question/24287773

Find the 70th term of the following arithmetic sequence 4,12,20,28

Answers

Answer:

556

Step-by-step explanation:

formula

L = a + (n - 1)*d

Givens

n = 70

a = 4

d = 8

Solution

t = 4 + (70 - 1)*8

t = 4 + 69*8

t = 4 + 552

t = 556

The length of a picture frame is 1cm less than twice the width(frame is NOT a square). The area is 28cm^2. Find the length and width of the picture frame.

Answers

Answer:

length is 7cm, and the width is 4cm

Step-by-step explanation:

The length of a picture frame is 1cm less than twice the width(frame is NOT a square). The area is 28cm^2. Find the length and width of the picture frame.

The area of the frame = Length * Width

A = LW

If the length of a picture frame is 1cm less than twice the width, then;

L = 2W - 1

Substitute into the formula;

A = (2W-1)W

A = 2W^2 - W

28 = 2W^2 - W

2W^2 - W - 28 = 0

2W^2 - 8W +7W- 28 = 0

2W(W-4)+7(W-4) = 0

2W+7 = 0 and W - 4 = 0

W =- -7/2 and W = 4

Width cannot be negative

W = 4cm

Since A = LW

L = A/W

L = 28/4

L = 7cm

Hence the length is 7cm, and the width is 4cm

Help please! I’ll give brainliest too!

Answers

Answer:

y-intercept: -5

Slope: 4

Equation: y = 4x - 5

Step-by-step explanation:

✔️The y-intercept is the value of y when x = 0. From the table of values, it shows that when x = 0, y = -5. Therefore:

y-intercept (b) = -5

✔️using two pairs from the table, (1, -1) and (2, 3):

[tex] Slope (m) = \frac{y_2 - y_1}{x_2 - x_1} = \frac{3 -(-1)}{2 - 1} = \frac{4}{1} = 4 [/tex]

Slope = 4

✔️To write an equation for the function, substitute m = 4, and b = -5 into y = mx + b.

Thus:

y = 4x +(-5)

y = 4x - 5

What subfield of mathematics requires the most spatial reasoning?
No answer needed, just need to get rid of all my points.

Answers

Answer:

brainlest?

Step-by-step explanation:

......

Answer: I looked it up and got a couple of answers of spatial reasoning. Don’t know if that helps but yeah thats what I got lol

Step-by-step explanation:

Jada sells ground paprika.

Her weekly profit (in dollars) as a function of the amount of paprika she sold that week (in kilograms) is graphed.

What is Jada's profit if she sells 60 kilograms of paprika?

Answers

Answer:

200

Step-by-step explanation:

Find 60 kilos then just follow the line up till you reach the blue line  

1) Given: H is the midpoint of EG
mZE = mZG
G
D
Prove: ADEH - AFGH
H.
E
F

Answers

It is E

Duhhhhhhhhhhhhh

There are 4 sharks and 5 dolphins. Write the ratio of sharks to dolphins. Then find and interpret the value of the ratio.

Answers

Answer:

here is the ratio  1 : 1.25   (sharks: dolphins)

Step-by-step explanation:

The ratio of sharks to dolphins is 4 : 5

How to obtain real measurements from the ratio of two measurements?

Suppose the  real measurements were "a" and "b"

This shows that to get the real measurements from the given ratio, we need to assume to have some factor possibly cancelled from both the numerator and the denominator.

Thus, a = px, b = qx

Given Number of sharks = 4

Number of dolphins = 5

Therefore, the ratio of sharks to dolphins

= 4 : 5

Or  1 : 1.25

Number of animals = number of sharks + number of dolphins

Number of animals = 4 + 5 = 9

Learn more about ratio here:

brainly.com/question/186659

#SPJ2

help asap Its distributive property so 6x55 i need the second part how to write it out like
(and then) a number + some other number and then what it equals 5th grade math

Answers

Answer:

I don't know exactly what you need but I have two ways.

Step-by-step explanation:

if you need to make an example: 6x55+ 6(3f-12)= or something along those lines.

or if you just need that answer then 330

I'm sorry if that's not what you were wondering

ples halp ples tysm....

Answers

10

Edge 2020-2021 how is everyone’s day

Please help me:):):)

Answers

Answer:

c - 8 ≥ 25

Step-by-step explanation:

HELP ASAP PLZ NEED IR SNDWWRED AS PAST AS POSSIBLE​

Answers

Answer:

I would say, 2.5

Step-by-step explanation:

Because the calculator said 2.67

PLEASE HELP NOBODY EVER ANSWERS MY QUESTIONS Rip van Winkle has fallen asleep for a very long time.

The length of his beard (in millimeters) as a function of time (in weeks) is graphed.

How long was Rip van Winkle's beard when he fell asleep?

Answers

Answer:

10 millimeters

Step-by-step explanation:

Don't listen to the other answerer who was trolling, I will actually help you. To find how long his beard was when he fell asleep, we need to find the y-intercept. The y-intercept marks how long his beard was right when he fell asleep. From looking at the graph, we can see that the y-intercept is 10. This means his beard was 10 millimeters long when he fell asleep. I hope this helps!

Answer:

10 meters

Step-by-step explanation:

if you look at the start os the graph, I shows that the Y intercept is 10, therefore, the answer is 10 meters.

- a friendly 8th grader :)

C(x) = 5x^2 + x + 7 and
d(x) = x^2 – 10
d(c(3))

Answers

Answer:

d(c(3))=30I5

Step-by-step explanation:

C(3)=5×9+3 +7=55

d(c(3))= ( 55)^2-10= 3O 15

Need help on this one.
I JUST DONT WHAT TO DO IT

Answers

Answer: Bottom Left

Step-by-step explanation:

Answer:

bottom left

Step-by-step explanation:

cuz it makes sense

Don’t worry about the one at the bottom BUT HELP MEEEEE

Answers

Answer:

e. 79/30     f.   18.2

Step-by-step explanation:

1) A person can pay $16 for a membership to the science museum and then go to the
museum for just $3 per visit. What is the maximum number of visits a member of the
science museum can make for a total cost of $37?
visits


Please hurry

Answers

7 visits

Step-by-step explanation:

All I did was minus 16 from 37 to get 21, then divided that by 3.

which graph represents the solution to this inequality

Answers

Answer:

C

Step-by-step explanation:

Answer

it is: C

Step-by-step explanation:

two equations in standard for equivalent to x+y=-10

Answers

Y=-x-10 orrrr y=x+10

A carnival sold 450 tickets on Saturday. The ticket sales showed that 126 of the ticket sales were adult tickets. What percent of the tickets sold on Saturday were adult tickets?!PLEASE ANSWER!!!

Answers

Answer:

28%

Step-by-step explanation:

hope this helps, have a good day

Bargains warehouse has 3 shirt special. Christina bought 3 shirts on sales for $35.97 if she would have only bought one shirt, she would have paid $16.24. How much money is Christina saving on each shirt by buying 3 shirts on a special?

Answers

Answer:

12.75 Its correct

Step-by-step explanation:

Answer:

12.75

Step-by-step explanation:

Reduce the ratio to the lowest term: 60 : 75

Answers

the answer is 4:5

hope this helps!

Answer:

4 : 15 is the answer for 60 : 75 to the lowest term

Simplifying radicals! Please help me & Show WORK

Answers

Answer:

Solving the radical [tex]4\sqrt{2}(-4\sqrt{15}+3\sqrt{18})[/tex] we get [tex]\mathbf{-16\sqrt{30}+72}[/tex]

Step-by-step explanation:

We need to simplify the radical: [tex]4\sqrt{2}(-4\sqrt{15}+3\sqrt{18})[/tex]

Prime factors of 18 are: 2x3x3

Replacing [tex]\sqrt{18}[/tex] with its factors

[tex]4\sqrt{2}(-4\sqrt{15}+3\sqrt{18})\\=4\sqrt{2}(-4\sqrt{15}+3\sqrt{2\times3\times3})\\=4\sqrt{2}(-4\sqrt{15}+3\sqrt{2\times3^2})[/tex]

We know that [tex]\sqrt{3^2}=3[/tex]

[tex]=4\sqrt{2}(-4\sqrt{15}+3\times3\sqrt{2})\\=4\sqrt{2}(-4\sqrt{15}+9\sqrt{2})[/tex]

Multiplying [tex]4\sqrt{2}[/tex] with terms inside the bracket

[tex]=4\sqrt{2}(-4\sqrt{15})+4\sqrt{2}( 9\sqrt{2}))\\=-16\sqrt{2}\sqrt{15}+36\sqrt{2} \sqrt{2}[/tex]

We know that [tex]\sqrt{2} \sqrt{2}=2[/tex]

[tex]=-16\sqrt{2*15}+36(2)\\=-16\sqrt{30}+72[/tex]

So, solving the radical [tex]4\sqrt{2}(-4\sqrt{15}+3\sqrt{18})[/tex] we get [tex]\mathbf{-16\sqrt{30}+72}[/tex]

A waiter earned a 7% tip. What decimal is equivalent to 7%?
Record your answer and fill in the bubbles on your answer document. Be sure to use the
correct place value.

Answers

7% in decimal form is 0.07

please help!! it’s due soon:(

Answers

Answer:

Step-by-step explanation:

AC ≅ AD ; BC≅ BD                      Given

AB ≅ AB                                        Reflexive property of congruence

ΔACB ≅ ΔADB                              Side Side Side Postulate

-3(2+4k)+7(2k-1)

A. 2k-13
b. 8k-13
c. 2k+13
d. 2k-7

Answers

9514 1404 393

Answer:

  A.  2k -13

Step-by-step explanation:

-3(2 +4k) +7(2k -1)

= -6 -12k +14k -7 . . . . . . eliminate parentheses

= (-12 +14)k -6 -7 . . . . . . group like terms

= 2k -13 . . . . matches choice A

I’m pretty sure it’s a hope it helps dude

Help people help!!!!

Answers

Answer:

I think that it is

C

Please let me know if it is not correct!!!!

Answer:

A would most likly be the answer

Step-by-step explanation:

because in the equation sinse A =  -5 1/4 which is whe he was at the end hopefully you understand

4a.
An iron bar is heated. Its length, L, in millimetres can be modelled by a linear function, L=mT+c, where T is the temperature measured in degrees Celsius (°C).
At 150°C the length of the iron bar is 180 mm.
Write down an equation that shows this information.

4b.
At 210°C the length of the iron bar is 181.5 mm.
Write down an equation that shows this second piece of information.

4c.
At 210°C the length of the iron bar is 181.5 mm.
Hence, find the length of the iron bar at 40°C.

(really need most help on last one)

Answers

Answer and Step-by-step explanation:

Find f(−5) if f(x)=|x+1|. Type a numerical answer in the space provided. Do not type spaces in your answer.

Answers

Answer:   4

===============================================

Work Shown:

f(x) = |x+1|

f(-5) = |-5+1| .... x is replaced with -5

f(-5) = |-4|

f(-5) = 4

Help me please solve this

Answers

9514 1404 393

Answer:

  a) no

  b) yes

Step-by-step explanation:

a) You cannot draw the graph around x=0 without lifting your pencil. The function is not continuous at x=0.

__

b) You can draw the graph around x=1 without lifting your pencil. The function is continuous at x=1.

_____

Additional comment

In technical terms, the limit from the left at x=0 is 2; the limit from the right is 3. These are different, so the function is not continuous there.

On the other hand, the left and right limits at x=1 are the same (both 2), and are equal to the value of the function at that point (f(1)=2). Hence, the function is continuous at x=1.

Other Questions
PLS HELP DUE SOON!! (retest) will give brainliest Pls help ASAP I will make you brainleist 20PTS Spanish grammar questions!! :)1. Choose the English equivalent for the following word: hacer-to do, to make-to know how-to run-to learn2. Choose the sentence that is grammatically correct:-Ella abres los regalos. -Tu abro los regalos. -Tu abres los regalos.-Elisa abrimos los regalos. 3. Fill in the blank with the correct conjugation of the verb recibir. -recibo-recibes-reciben-reibimos4. Fill in the blank with the correct conjugation of the verb correr.Nosotros ___ cinco kilometros cada dia.-corremos-corren-corro-correis People exercise power by voting for political representatives.Citizens choose people to represent them in government.Which principle of the constitution is being described? QUICKKK PLEASE HELP!!!! Q:43c +10d=????? Make the expression a perfect square u^2 + 10u + HELP PLEASE!!!!!!!!!!!!!!! Which source does most campaign money come from? A.private sourcesB.public funding Soft money can come from individuals only?true or false examples of sound to radiant energy A frequency generator sends a 550Hz sound wave through both water and ice. What is the difference in wavelength between the wave produced in ice and the wave produced in water? What is the first step to solve the following system of equations using substitution? X-y=-12x-y=3A.) Solve the first equation for x.B.) Divide the second equation by 2.C.) Multiply the first equation by 2.D.) Add the two equations together. please help! one easy khan question How are health education ,population education and environment interrelated on science and technological aspect? Is this statement true or false?Blacks who tried to register to vote were given impossible questions to answer or charged a poll tax they could not afford.a: trueb: false The equation of the blue line is y=-x+5. Manipulatethe orange line by setting the sliders so its slope, m, is-1 and its y-intercept, b, is-3.Does the system appear to have a solution after thechanges?Yes. The lines intersect at one point.Yes. The lines intersect at many points.No. The lines do not seem to intersect. g(x)=x2, find g(1) What would NOT be an accurate title for this list?"SUPPORTED INDEPENDENCEWANTED TO MAKE THEIR OWN RULES & LAWSBELIEVED REVOLUTIONARY WAR WAS NECESSARY IN ORDERTO BREAK FREE FROM TYRANNY"Sons of LibertyPatriotsLoyalistsLiberty Boys What responsibilities can you fulfill without waiting until you turn 18 years old? hey ur name is sandra or alexam i rightcomment pleas can you guys help me please the things are ABor C