There will be many polynomials of degree 2 that pass through the points (1, 7) and (3, 9). The situation can be described by a system of two linear equations in three variables that has many solutions. Find an equation (involving a parameter r) that represents this family of polynomials. (Let the coefficient of the x2 term in the equation be r.)

Answers

Answer 1
Answer:

Answer:

Any polynomial of the form f(x)=rx²+(1-4r)x+(3r+6) passes through these points.

Step-by-step explanation:

Let f(x)=rx²+bx+c be a polynomial that passes through (1,7) and (3,9). This means that f(1)=7 and f(3)=9, that is,

f(1)=r(1)²+b(1)+c=r+b+c=7, and

f(3)=r(3)²+b(3)+c=9r+3b+c=9

We have the equations r+b+c=7 and 9r+3b+c=9. Substract the second equation minus 9 times the first to obtain -6b-8c=-54, then 6b+8c=54 or equivalently b=9-4c/3.

Substract the second equation minus 3 times the first to obtain 6r-2c=-12. Then 2c=6r+12, thus c=3r+6. We have written c in terms of r. Substitute in b=9-4c/3 to obtain b=9-4(r+2)=-4r+1. The polynomial acquires the form

f(x)=rx²+(1-4r)x+(3r+6).


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Answers

Answer:

what is the Question

Step-by-step explanation:

Find the derivation of y=sin (2x2 + 3x-4)<br />a. -cos (4x +3) b. -(6x2+3) cos (2x3+3x-4) c. Cos (2x3+3x-4)<br />d. (6x3+3) cos (2x3+3)<br />​

Answers

Let y = f(x)

f(x) = sin x

g(x) = (2x^2 + 3x - 4)

Use the chain rule.

We want y' = f' (g(x)) • g'(x).

y' = cos(2x^2 + 3x - 4) • (4x + 3)

Done.

Polygraph lie-detector machines are commonly used in criminal investigations. The device measures nervous excitement, operating on the idea that if a person is telling the truth they will remain calm. The American Polygraph Association claims that polygraphs accurately identify liars 90% of the time. In other words, if a person lied the test results will be positive 90% of the time. Although the polygraph test is good at identifying liars, there is a 50% chance that the polygraph test will say a truthful person is lying. A police force wants to predict the accuracy of lie-detector tests for 1,000 suspected criminals. Assume that 700 per 1,000 suspected criminals tell the truth during polygraph tests. Lie Truth Row Totals Test result: negative P Test result: postive Q Column Totals 1,000 Barber, N. (2013). Do Lie Detectors Work? Psychology Today . What is the value of Q?

Answers

Answer:

The value of Q is 350.

Step-by-step explanation:

Denote the events as follows:

X = the test is positive

Y = the test is negative

A = the person is telling the truth

B = the person is telling a lie.

It is provided that:

P (B ∩ X) = 0.90

P (A ∩ Y) = 0.50

Then:

P (B ∩ Y) = 1 - P (B ∩ X) = 1 - 0.90 = 0.10

P (A ∩ X) = 1 - P (A ∩ Y) = 1 - 0.50 = 0.50

To test the accuracy of lie-detector a police officer tests 1000 suspected criminals.

It is assumed that 700 per 1,000 suspected criminals tell the truth during polygraph tests.

The table needed to be completed is:

                       Truth (A)        Lie (B)         TOTAL

Positive (X)           Q                 __               __

Negative (Y)         __                 P                __

TOTAL                   __                __               __

For the 1000 suspected criminals selected complete the table as follows:

Given:

                       Truth (A)        Lie (B)         TOTAL

Positive (X)           Q                 __               __

Negative (Y)         __                 P                __

TOTAL                  700              300           1000

n (A ∩ X) = P (A ∩ X) × n (A)

               = 0.50 × 700

               = 350

n (A ∩ Y) = P (A ∩ Y) × n (A)

               = 0.50 × 700

               = 350

n (B ∩ X) = P (B ∩ X) × n (B)

               = 0.90 × 300

               = 270

n (B ∩ Y) = P (B ∩ Y) × n (B)

               = 0.10 × 300

               = 30

n (X) = n (B ∩ X) + n (A ∩ X)

        =  270 + 350

        = 620

n (Y) = n (B ∩ Y) + n (A ∩ Y)

        =  30 + 350

        = 380

Complete table is:

                         Truth (A)        Lie (B)        TOTAL

Positive (X)       Q = 350           270            620

Negative (Y)        350             P = 30          380

TOTAL                  700               300            1000

Thus, the value of Q is 350.

A basket of fruit contains 4 bananas, 3 apples, and 5 oranges. You intend to draw a piece of fruit from the basket, keep it, and then draw a 2nd piece of fruit from the basket. What is the probability of selecting two oranges in a row from the basket if you are blindfolded?

Answers

Answer: 5/33

Step-by-step explanation: There are 12 fruits and 5 are oranges.

If you draw an orange, then there are 11 fruits and 4 oranges. (5/12)x(4/11)=20/132 or 5/33 in simplest form.

This is so easy but i can find this in the internet but what i wanna know is what goes in the Missing blank 50 take away ? equals 20

Answers

50 minus 30 is 20.
You could subtract 20 from 50 to see what you would get, and then just plug it in to double check.

Solve x -2/3(3x - 4) + 3x = 5/6 is x -19/6, 11/6, 21/6, 29/6

Answers

Answer:

x=-11/12

Step-by-step explanation:

Given an equation for x

x -2/3(3x - 4) + 3x = 5/6

We are asked to find the value of x.

We use equation rules to solve

To get rid of denominator in fraction, let us multiply the whole equation by 6.

6x-4(3x-4) +18x = 5

Simplify:

-6x+18x+16 =5

12x = 5-16 = -11

x = -11/12

Answer:

- 11/6

Step-by-step explanation: