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3 years ago

Given that ƒ(x) = x² + 4x, evaluate ƒ(-2).

2 answers:

8 0

The way to do this is to plug in -2 everything there is an x

-2²+4(-2)

4+4(-2)

4+-8

-4 is your answer

I hope I've helped!

Furkat [3]3 years ago

5 0

The believe your answer is -4.

I hope this helps!

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A shooting star forms a right triangle with the Earth and the Sun, as shown below:

STatiana [176]

Answer:

- The scientist can use these two measurements to calculate the distance between the Earth and the Sun by applying one of the trigonometric functions: Cosine of an angle.

- The scientist can substitute these measurements into $cos\alpha=\frac{adjacent}{hypotenuse}$ and solve for the distance between the Earth and the Sun.

Step-by-step explanation:

Let's assume that the right triangle formed is like the one shown in the figure attached, where "d" represents the distance between the Earth and the Sun.

Then:

The scientist can use only these two measurements to calculate the distance between the Earth and the Sun by applying one of the trigonometric functions: Cosine of an angle.

The scientist can substitute these measurements into $cos\alpha=\frac{adjacent}{hypotenuse}$ , and solve for the distance "d".

Knowing that:

$\alpha=x\°\\adjacent=d\\hypotenuse=y$

Then:

$cos(x\°)=\frac{d}{y}$

And solving for "d":

$ycos(x\°)=d$

3 0

3 years ago

2. Compare the function ƒ(x) = –x^2 + 4x – 5 and the function g(x), whose graph is shown. Which function has a greater absolute

sergij07 [2.7K]

Answer:

g(x)

Step-by-step explanation:

The vertex of g(x) as shwon in the graph is located in the point wich coordinates are (3.5,6.25) approximatively

We need to khow the coordinates of f(x) vertex

Here is a way without derivating:

f(x) = -x² + 4x -5

let a be the leading factor, b the factor of x and c the constant:

a= -1
b= 4
c= -5

The coordinates of a vertex are: ( $\frac{-b}{2a}$ , f( $\frac{-b}{2a}$ ) )

-b/2a = -4/ (-1*2) = 4/2 = 2

f(2)= -2²+4*2-4 = -4+4-4 = -4

obviosly f(x) has a minimum wich less than g(x)'s maximum

3 0

3 years ago

Convert the recursive equation that is below into an explicit equation where a is the initial value and the time elapsed is 1 ye

aleksley [76]

Answer:

f(n) = a+200(n -1)

Step-by-step explanation:

The constant difference between terms indicates the sequence is an arithmetic one. The explicit formula for an arithmetic sequence is ...

an = a1 + d(n -1)

where a1 is the first term and d is the common difference.

Your first term is "a", and your common difference is 200, so the n-th term of the sequence is ...

an = a + 200(n -1)

Written as a function of n, this is ...

f(n) = a + 200(n -1)

_____

Based on the problem description, we cannot tell how n relates to time, so we have created an f(n) that gives the same result as the recursive definition of f(n).

8 0

3 years ago

Work out the estimate 5.1×98

Zolol [24]

5.1 is close to 5 to we'll take 5
Do 98 x 5 = 490
Actual answer: 499.8
Compare them, it's close enough!

8 0

3 years ago

Read 2 more answers

A manufacturing company builds construction machinery. It sells 10 machines for $18,100 and 20 machines for $26,600. Which equat

Anon25 [30]

<h3>Answer:</h3>

D. R(x) = 850x +9600

<h3>Step-by-step explanation:</h3>

Selling 10 more machines increased revenue from $18100 to $26600, an increase of ...

... $26,600 -18,100 = $8,500

That is, the revenue increased by $8500/10 = $850 per machine.

Only one answer choice has this number in it:

... D. R(x) = 850x+9600

_____

<em>Check</em>

R(10) = 850·10 +9600 = 8500 +9600 = 18,100 . . . . OK

R(20) = 850·20 +9600 = 17000 +9600 = 26,600 . . . . OK

_____

<em>Comment on answer selection</em>

On multiple-choice questions, it is rarely necessary to work out the solution to the problem completely. Usually, it is sufficient to find the one number that discriminates between correct and incorrect answers.

In real life, answers are rarely multiple-choice. You are required to work the problem completely and to figure out how to tell if your answer is correct.

Here, we have worked the problem far enough to find the slope, the amount by which revenue increases when sales increases by 1 unit. The intercept can be found different ways. One of them is to see what number makes the revenue match for one of the "x" values:

... R(10) = 850·10 +b = 18100

... b = 18100 -8500 = 9600

so ...

... R(x) = 850x +9600

We can check this answer by computing R(20), as we have above.

8 0

3 years ago

Read 2 more answers