1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
stepan [7]
2 years ago
13

If you have a cubic polynomial of the form y = ax^3 + bx^2 + cx + d and lets say it passes through the points (2,28), (-1, -5),

(4, 220), and (-2, -20) what would the coefficients a, b, c, and d equal? So confused, I'd greatly appreciate help! Thank you!
Mathematics
2 answers:
nikklg [1K]2 years ago
6 0

Step-by-step explanation:

<u>Step 1:  Solve using the first point</u>

<em>(2, 28)</em>

28 = a(2)^3 + b(2)^2 + c(2) + d

28 = 8a + 4b + 2c + d

<u>Step 2:  Solve using the second point</u>

<em>(-1, -5)</em>

-5 = a(-1)^3 + b(-1)^2 + c(-1) + d

-5 = -a + b - c + d

<u>Step 3:  Solve using the third point</u>

<em>(4, 220)</em>

220 = a(4)^3 + b(4)^2 + c(4) + d

220 = 64a + 16b + 4c + d

<u>Step 4:  Solve using the fourth point</u>

<em>(-2, -20)</em>

-20 = a(-2)^3 + b(-2)^2 + c(-2) + d

-20 = -8a + 4b - 2c + d

<u>Step 5:  Combine the first and fourth equations</u>

<u />28 - 20 = 8a - 8a + 4b + 4b + 2c - 2c + d + d

8 = 8b + 2d

8 - 8b = 8b - 8b + 2d

(8 -8b)/2 = 2d/2

4 - 4b = d

<u>Step 6:  Solve for c in the second equation</u>

-5 + 5 = -a + b - c + d + 5

0 + c = -a + b - c + c + d + 5

c = -a + b + d + 5

<u>Step 7:  Substitute d with the stuff we got in step 5</u>

c = -a + b + (4 - 4b) + 5

c = -a + b + 4 - 4b + 5

c = -a - 3b + 9

<u>Step 8:  Substitute d and c into the first equation</u>

<u />28 = 8a + 4b + 2(-a - 3b + 9) + (4 - 4b)

28 = 8a + 4b - 2a - 6b + 18 + 4 - 4b

28 - 22 = 6a - 6b + 22 - 22

6 / 6 = (6a - 6b) / 6

1 + b = a - b + b

1 + b = a

<u>Step 9:  Substitute a, b, and c into the third equation</u>

220 = 64(1 + b) + 16b + 4(-(1 + b) - 3b + 9) + (4 - 4b)

220 = 64 + 64b + 16b + 4(-1 - b - 3b + 9) + 4 - 4b

220 - 100 = 60b + 100 - 100

120 / 60 = 60b / 60

2 = b

<u>Step 10:  Find a using b = 2</u>

a = b + 1

a = (2) + 1

a = 3

<u>Step 11:  Find c using a = 3 and b = 2</u>

c = -a - 3b + 9

c = -(3) - 3(2) + 9

c = -3 - 6 + 9

c = 0

<u>Step 12:  Find d using b = 2</u>

d = 4 - 4b

d = 4 - 4(2)

d = 4 - 8

d = -4

Answer:  a = 3, b = 2, c = 0,d = -4

Naya [18.7K]2 years ago
3 0

Answer:

a = 3

b = 2

c = 0

d = -4

Step-by-step explanation:

Form 4 equations and solve simultaneously

28 = a(2)³ + b(2)² + c(2) + d

28 = 8a + 4b + 2c + d (1)

-5 = -a + b - c + d (2)

220 = 64a + 16b + 4c + d (3)

-20 = -8a + 4b - 2c + d (4)

(1) + (4)

28 = 8a + 4b + 2c + d

-20 = -8a + 4b - 2c + d

8 = 8b + 2d

d = 4 - 4b

Equation (2)

c = -a + b + d + 5

c = -a + b + 4 - 4b+ 5

c = -a - 3b + 9

28 = 8a + 4b + 2c + d (1)

28 = 8a + 4b + 2(-a - 3b + 9) + 4 - 4b

28 = 6a - 6b + 22

6a - 6b = 6

a - b = 1

a = b + 1

220 = 64a + 16b + 4c + d (3)

220 = 64(b + 1) + 16b + 4(-b - 1 - 3b + 9) + 4 - 4b

220 = 60b + 100

60b = 120

b = 2

a = 2 + 1

a = 3

c = -3 - 3(2) + 9

c = 0

d = 4 - 4(2)

d = -4

You might be interested in
In a sample of seven cars, each car was tested for nitrogen-oxide emissions (in grams per mile) and the following results were o
ad-work [718]

The question is incomplete. Here is the complete qeustion.

In a sample of seven cars, each car was tested for nitrogen-oxide emissions (in grams per mile) and the following results were obtained: 0.10 0.13 0.16 0.15 0.14 0.008 0.15

(a) Construct a 99% confidence interval for the mean nitrogen-oxide emissions of all cars.

(b) If the EPA requires that nitrogen-oxide emissions be less than 0.165 g/mi, based on the 99% confidence interval in (a), can we safely conclude that this requirement is being met?

Answer: (a) 0.089 ≤ μ ≤ 0.171

(b) No

Step-by-step explanation:

(a) To determine the confidence interval, first calculate the mean (X) and standard deviation (s) of the sample

X = \frac{0.1+0.13+0.16+0.15+0.14+0.08+0.15}{7}

X = 0.13

s = \sqrt{\frac{(0.1-0.13)^{2} + (0.13 - 0.13)^{2} + ... + (0.15 - 0.13)^{2}}{7-1} }

s = 0.029

The degrees of freedom is

N - 1 = 7 - 1 = 6

And since the confidence is of 99%:

α = 1 - 0.99 = 0.01

α/2 = 0.01/2 = 0.005

The t-test statistics for t_{6,0.005} is 3.707

(Value found in the t-distribution table)

Now, calculate Error:

E = t_{6,0.005} . \frac{s}{\sqrt{N} }

E = 3.707. \frac{0.029}{\sqrt{7} }

E = 0.041

The interval will be:  

0.13 - 0.041 ≤ μ ≤ 0.13+0.041

0.089 ≤ μ ≤ 0.171

(b) No, because according to the interval, the nitrode-oxide emissions range from 0.089 to 0.171, which is greater than required by EPA.

7 0
3 years ago
Ludwig borrowed $700,000 for a period of 2 years. His interest rate is 10%. How much interest will Ludwig pay in all?
harkovskaia [24]
By yearly interest or monthly? Yearly: he pays 840000 monthly: 2380000 sorry it’s so long just tryna help a bruthu or sister out I didn’t check yo username
5 0
3 years ago
A bowl contains 7 marbles of various colors consisting of green, brown, and red.
ZanzabumX [31]

Answer:

3/7

Step-by-step explanation:

7-4=3

7 0
2 years ago
A sphere and a cylinder have the same radius and height. The volume of the cylinder is 21m. what is the volume of the sphere.​
Goshia [24]

Answer:

The volume of the sphere is 14m³

Step-by-step explanation:

Given

Volume of the cylinder = 21m^3

Required

Volume of the sphere

Given that the volume of the cylinder is 21, the first step is to solve for the radius of the cylinder;

<em>Using the volume formula of a cylinder</em>

The formula goes thus

V = \pi r^2h

Substitute 21 for V; this gives

21 = \pi r^2h

Divide both sides by h

\frac{21}{h} = \frac{\pi r^2h}{h}

\frac{21}{h} = \pi r^2

The next step is to solve for the volume of the sphere using the following formula;

V = \frac{4}{3}\pi r^3

Divide both sides by r

\frac{V}{r} = \frac{4}{3r}\pi r^3

Expand Expression

\frac{V}{r} = \frac{4}{3}\pi r^2

Substitute \frac{21}{h} = \pi r^2

\frac{V}{r} = \frac{4}{3} * \frac{21}{h}

\frac{V}{r} = \frac{84}{3h}

\frac{V}{r} = \frac{28}{h}

Multiply both sided by r

r * \frac{V}{r} = \frac{28}{h} * r

V = \frac{28r}{h} ------ equation 1

From the question, we were given that the height of the cylinder and the sphere have equal value;

This implies that the height of the cylinder equals the diameter of the sphere. In other words

h = D , where D represents diameter of the sphere

Recall that D = 2r

So, h = D = 2r

h = 2r

Substitute 2r for h in equation 1

V = \frac{28r}{2r}

V = \frac{28}{2}

V = 14

Hence, the volume of the sphere is 14m³

4 0
3 years ago
Read 2 more answers
Mrs. O'Malley is setting up for a party. Each adult will get 2 glasses, and each child will get 1 glasses. There are 8 Adult and
malfutka [58]

1 adult=2

1 child=1

multiply 2*8=16 adult glasses

multiply 1*5=5 child glasses

in total she needs 21 glasses

hope I was helpful

5 0
3 years ago
Other questions:
  • If f={(2,5),(3,2)(4,6),(5,1),(7,2), then f is a function. True or flase
    11·2 answers
  • Find the midpoint M of the line segment joining thee Point S =(6,-7) and I =(-8,3)​
    14·1 answer
  • community swimming pool has a deep end and a shallow end. The volume of water in the deep end can be represented by (2x^3 + 12x2
    11·1 answer
  • Can you answer this plz thanks
    11·1 answer
  • 5. Use a unit multiplier to convert 3.5 g to milligrams.​
    11·1 answer
  • Niamh runs 6 km in 30-minutes what is the average speed in km h
    14·2 answers
  • This figure consists of a rectangle and semicircle.
    12·1 answer
  • Will give brainliest answer please help
    8·1 answer
  • What is the sum of 2/3+(-1/3)
    11·2 answers
  • What coordinates on the unit circle are associated with the angle measure?
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!