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2 years ago

Given f'(x) = (1 − x)(4 − x), determine the intervals on which f(x) is increasing or decreasing.

Mathematics

2 answers:

Sophie [7]2 years ago

8 0

The critical points are at x = 1 and x = 4 giving you the intervals (-inf, 1), (1, 4) and (4, inf).

By substituting x values in these 3 intervals, you can see that f'(x) is positive in the first and third intervals and negative in the second interval.

This means that f(x) is increasing in the first and third intervals and decreasing in the second interval.

The answer is D.

IgorC [24]2 years ago

6 0

To the risk of sounding redundant.

notice, your critical points are 1 and 4, so you check the regions about, namely, do a first-derivative test on them, check the picture below.

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A tank containing 1140.8 gallons can be emptied in 92 minutes. How many gallons is that per minute?

Ivan

Answer:

Divide the volume of the tank (10,000 gallons) by the filling rate of 250 gallons/minute and you will Hours = hr x min x 3785 ml x 55 gal = 208175 = 115.6 hrs.

Step-by-step explanation:

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7 0

2 years ago

How do you solve this? r^2+32=12r

Andre45 [30]

Answer:

r = {-8, -4}

Step-by-step explanation:

Simplifying

r2 = -32 + -12r

Solving

r2 = -32 + -12r

Solving for variable 'r'.

Reorder the terms:

32 + 12r + r2 = -32 + -12r + 32 + 12r

Reorder the terms:

32 + 12r + r2 = -32 + 32 + -12r + 12r

Combine like terms: -32 + 32 = 0

32 + 12r + r2 = 0 + -12r + 12r

32 + 12r + r2 = -12r + 12r

Combine like terms: -12r + 12r = 0

32 + 12r + r2 = 0

Factor a trinomial.

(8 + r)(4 + r) = 0

Subproblem 1

Set the factor '(8 + r)' equal to zero and attempt to solve:

Simplifying

8 + r = 0

Solving

8 + r = 0

Move all terms containing r to the left, all other terms to the right.

Add '-8' to each side of the equation.

8 + -8 + r = 0 + -8

Combine like terms: 8 + -8 = 0

0 + r = 0 + -8

r = 0 + -8

Combine like terms: 0 + -8 = -8

r = -8

Simplifying

r = -8

Subproblem 2

Set the factor '(4 + r)' equal to zero and attempt to solve:

Simplifying

4 + r = 0

Solving

4 + r = 0

Move all terms containing r to the left, all other terms to the right.

Add '-4' to each side of the equation.

4 + -4 + r = 0 + -4

Combine like terms: 4 + -4 = 0

0 + r = 0 + -4

r = 0 + -4

Combine like terms: 0 + -4 = -4

r = -4

Simplifying

r = -4

Solution

r = {-8, -4}

3 0

2 years ago

Two boats left a base camp at bearing of S60°E and S50°W at speeds of 50km/h and 70km/h respectively. Find the distance between

ivolga24 [154]

Answer:

197.93 km

Step-by-step explanation:

Let the base camp is point A and boats' locations after two hours are points B and C.

By connecting the three points together we get a triangle ABC with sides:

AB = 50*2 = 100 km
AC = 70*2 = 140 km

The angle between AB and AC is:

60 + 50 = 110 degrees (opposite directions from south)

We are looking for the distance BC, which can be found by using the law of cosines:

BC² = AB² + AC² - 2AB*AC*cos ∠BAC

BC² = 100² + 140² - 2*100*140*cos 110°
BC² = 39176.56 (rounded)
BC = √39176.56 = 197.93 km (rounded)

The distance between the boats is 197.93 km.

7 0

1 year ago

Now try 50 for x. If x=50,what I'd y when y=x-20? Does that work with the other equation?

SSSSS [86.1K]

X= 50
Replace the x with the given number.
Y= 50-20
Y= 30

5 0

2 years ago

Ten members of the academic team went to a local restaurant after their contest. Each meal combo that came with soda cost $6.75,

Aneli [31]

Answer:

7 ordered with Soda;

3 ordered with water

Step-by-step explanation:

Given

$m \to$ With water

$n \to$ With Soda

So:

$m + n =10$ --- total

$5m + 6.75n = 62.25$ -- cost

Required

Find m and n

$m + n =10$

Make m the subject

$m = 10 - n$

Substitute $m = 10 - n$ in $5m + 6.75n = 62.25$

$5(10-n) +6.75n = 62.25$

$50-5n +6.75n = 62.25$

Collect like terms

$-5n +6.75n = 62.25 - 50$

$-5n +6.75n = 12.25$

$1.75n = 12.25$

Solve for n

$n = 12.25/1.75$

$n = 7$

$m = 10 - n$

$m = 10 - 7$

$m =3$

8 0

2 years ago