Does anyone know it?

Select the function that represents a parabola with zeros at x = –2 and x = 4, and y-intercept (0,–16). A ƒ(x) = x2 + 2x – 8 B ƒ

Ahat [919]

Answer:

D. $f(x) = 2\cdot x^{2}-4\cdot x -16$

Step-by-step explanation:

Any parabola is modelled by a second-order polynomial, whose standard form is:

$y = a\cdot x^{2}+b\cdot x + c$

Where:

$x$ - Independent variable, dimensionless.

$y$ - Dependent variable, dimensionless.

$a$ , $b$ , $c$ - Coefficients, dimensionless.

In addition, a system of three linear equations is constructed by using all known inputs:

(-2, 0)

$4\cdot a -2\cdot b + c = 0$ (Eq. 1)

(4, 0)

$16\cdot a + 4\cdot b +c = 0$ (Eq. 2)

(0,-16)

$c = -16$ (Eq. 3)

Then,

$4\cdot a - 2\cdot b = 16$ (Eq. 4)

$16\cdot a + 4\cdot b = 16$ (Eq. 5)

(Eq. 3 in Eqs. 1 - 2)

$a - 0.5\cdot b = 4$ By Eq. 4 (Eq. 4b)

$a = 4 + 0.5\cdot b$

Then,

$16\cdot (4+0.5\cdot b) + 4\cdot b = 16$ (Eq. 4b in Eq. 5)

$64 + 12\cdot b = 16$

$12\cdot b = -48$

$b = -4$

The remaining coeffcient is:

$a = 4 + 0.5\cdot b$

$a = 4 + 0.5\cdot (-4)$

$a = 2$

The function that represents a parabola with zeroes at x = -2 and x = 4 and y-intercept (0,16) is $f(x) = 2\cdot x^{2}-4\cdot x -16$ . Thus, the right answer is D.

6 0

3 years ago

Lucia has collected a set of data and calculated the mode to be 31. The set contains 87 numbers, but Lucia gets an email telling

miskamm [114]

The problem seems to be lacking a question. But looking for the same problem from another source, we're looking for the new mode after adding the 6 numbers into the data set.

Mode, in its most basic definition, is the number or data that is most repeated in a data set. For example, in {1, 1, 1, 2, 2, 3}, the most repeated number is 1. Hence, the mode is 1.

Now, going back to Lucia's problem. Prior to adding the 6 numbers, the mode of the set of 87 numbers is already 31. That means 31 is the most repeated number in the set. Checking the numbers that were added, since another count for 31 is to be added, even if the number of 23, 26, 28, and 40 are increased by 1. 31 will still be the most repeated number in the set. Hence, the mode is still 31.

Answer: 31

6 0

3 years ago

Will give brainliest if you are right.

miv72 [106K]

Answer:

x-int (2, 0)

y-int (0, 3)

General Formulas and Concepts:

The y-intercept is the y value when x = 0. Another way to reword that is when the graph crosses the y-axis.
The x-intercept is the x value when y = 0. Another way to reword that is when the graph crosses the x-axis.

Step-by-step explanation:

<u>Step 1: Locate x-intercept</u>

x-int (2, 0)

<u>Step 2: Locate y-intercept</u>

y-int (0, 3)

8 0

3 years ago

Use the scale of 1cm=45 km

alex41 [277]

Answer:

d = 7.4 cm is the distance between the two cities on the map.

Step-by-step explanation:

Let d = the distance measured on the map in centimeters (cm) between any two locations and let D be the actual distance in kilometers (km) between these same two locations.

Since the scale on the map is 1 cm = 45 km, then the ratio of the distance on the map to the actual distance is equal to 1cm/45 km; therefore the quotient of any measured distance d on the map divided by the corresponding much longer actual distance D would have to maintain (equal) this same ratio; In other words, we can set up the following proportion to solve for d given the actual distance D = 333 km as follows:

1 cm/45 km = d/D

Substituting, we get:

1 cm/45 km = d/333 km

d/333 km = 1 cm/45 km

(d/333 km)(333 km) = (1 cm/45 km)(333 km)

d = (333 km/45 km)(1 cm)

d = 7.4 cm is the distance between the two cities on the map.

Check:

1 cm/45 cm = d/333 km

1 cm/45 cm = 7.4 cm/333 km

1 cm/45 cm = 1 cm/45 km (Therefore, the distance ratio of the map has been maintained

3 0

2 years ago

X+2y-4. If;x=3, y=4, I need help solving this math problem

Savatey [412]

The answer is
3 + (2) (4) - 4
answer is 7

4 0

3 years ago