Sharon tried to solve an equation step by step.

9
9
15
5
​

=−3(e−2)
=−3e+6
=3e
=e
​

Step 1
Step 2
Step 3
​

Find Sharon's mistake.
Choose 1 answer:
Choose 1 answer:

Answer:

[tex]\bold{cos\dfrac{A}{2} = -\dfrac{1}{\sqrt3}}[/tex]

Step-by-step explanation:

Given that:

[tex]cosA=-\dfrac{1}3[/tex]

and

[tex]tanA > 0[/tex]

To find:

[tex]cos\dfrac{A}{2} = ?[/tex]

Solution:

First of all,we have cos value as negative and tan value as positive.

It is possible in the 3rd quadrant only.

[tex]\dfrac{A}{2}[/tex] will lie in the 2nd quadrant so [tex]cos\dfrac{A}{2}[/tex] will be negative again.

Because Cosine is positive in 1st and 4th quadrant.

Formula:

[tex]cos2\theta =2cos^2(\theta) - 1[/tex]

Here [tex]\theta = \frac{A}{2}[/tex]

[tex]cosA =2cos^2(\dfrac{A}{2}) - 1\\\Rightarrow 2cos^2(\dfrac{A}{2}) =cosA+1\\\Rightarrow 2cos^2(\dfrac{A}{2}) =-\dfrac{1}3+1\\\Rightarrow 2cos^2(\dfrac{A}{2}) =\dfrac{2}3\\\Rightarrow cos(\dfrac{A}{2}) = \pm \dfrac{1}{\sqrt3}[/tex]

But as we have discussed, [tex]cos\dfrac{A}{2}[/tex] will be negative.

So, answer is:

[tex]\bold{cos\dfrac{A}{2} = -\dfrac{1}{\sqrt3}}[/tex]

Answer:

  no

Step-by-step explanation:

If any x-value is repeated, the relation is not a function. Both x=4 and x=9 are repeated values, so this relation is not a function.

Answer:

(- 1, 4 )

Step-by-step explanation:

The line x + 2 = 0 can be expressed as

x + 2 = 0 ( subtract 2 from both sides )

x = - 2

This is the equation of a vertical line parallel to the y- axis and passing through all points with an x- coordinate of - 2

Thus (- 3, 4 ) is 1 unit to the left of - 2

Under a reflection in the line x = - 2

The x- coordinate will be the same distance from x = - 2 but on the other side while the y- coordinate remains unchanged.

Thus

(- 3, 4 ) → (- 1, 4 )

Answer:

The true true level of significance of this test is more than 0.01.

Step-by-step explanation:

No standard deviation and we are told that the investigator still used z rather than the more appropriate t - distribution.

This method of using the z-distribution when standard deviation is unknown will definitely result in a smaller critical value and this in turn simply means that the p-value will be smaller than what it should really be.

Thus, it means the critical value is getting closer to the mean value than the way it should be.

Therefore, means that for a given significance of 0.01 and using the z-distribution under this no standard deviation situation, the true true level of significance of this test is more than 0.01.

Answer:

0.4207149;0.7271136; 0.3063987; 0.04979 ; 0.01832

Step-by-step explanation:

For an exponential distribution:

IF Mean time until failure = 23100

λ = 1/ 23100 = 0.0000432900

What is the probability that a randomly selected fan will last at least 20,000 hours

x ≥ 20000

P(X ≥ 20000) = 1 - P(X ≤ 20000)

1 - P(X ≤ 20000) = [1 - (1 - e^(-λx))]

1 - P(X ≤ 20000) = [1 - (1 - e^(-0.0000432900*20000)

1 - P(X ≤ 20000) = [1 - (1 - 0.4207148)]

1 - P(X ≤ 20000) = 1 - 0.5792851

1 - P(X ≤ 20000) = 0.4207149

11) What is the probability that a randomly selected fan will last at most 30,000 hours?

x ≤ 30000

P(X ≤ 30000) = 1 - e^(-λx)

P(X ≤ 20000) = 1 - e^(-0.0000432900*30000)

= 1 - e^(−1.2987)

= 1 - 0.2728863

= 0.7271136

111) What is the probability that a randomly selected fan will last between 20,000 hours and 30,000 hours?

0.7271136 - 0.4207149 = 0.3063987

B) What is the probability that the lifetime of a fan exceeds the mean value by more than 2 standard deviations?

More than two standard deviation

X = 23100 + 2(23100) = 23100 + 46200 = 69300

Using the online exponential probability calculator :

P(X > 69300) = 0.04979

C) What is the probability that the lifetime of a fan exceeds the mean value by more than 3 standard deviations?

X = 23100 + 3(23100) = 23100 + 69300 = 92400

P(X > 92400) = 0.01832

Answer:

Hello,

The answer would be,

A union B = {3,6,9,12}

and A intersection B= {6,9}

Answer:

[tex]\huge\boxed{ A\ union \ B = \{3,6,8,9,12\}}[/tex]

[tex]\huge\boxed{A\ intersection \ B = \{6,9\}}[/tex]

Step-by-step explanation:

A = {3,6,9,12}

B = {6,8,9}

A∪B = {3,6,9,12} ∪ { 6,8,9}   [Union means all of the elements should be included in the set of A∪B]

=> A∪B = {3,6,8,9,12}

Now,

A∩B = {3,6,9,12} ∩ {6,8,9}  [Intersection means common elements of the set]

=> A∩B = {6,9}

Answer:

B

Step-by-step explanation:

11q + 5 ≤ 49

Subtract 5 from each side

11q + 5-5 ≤ 49-5

11q ≤44

Divide each side by 11

q ≤44/11

q≤4

There is a close circle at 4 because of the equals sign and the lines goes to the left

Answer:

B

Step 1:

To solve this, we need to isolate the variable q. To do so, we will subtract 5 from both sides of the inequality.

[tex]11q+5(-5)\leq 49(-5)\\11q\leq 44[/tex]

Step 2:

We divide both sides by 11 to get our q.

[tex]\frac{11q}{11}\leq \frac{44}{11} \\q\leq 4[/tex]

q ≤ 4

Step 3:

To find the correct graph, we need to know that a close circle means a ≤ or ≥ and an open one means a < or >. Here, we are using a ≤ so C and D are not our answers. Also remember that if the "arrow" is pointing left (<), then the arrow on the graph should be facing the left side. If the arrow is facing the right side, then that means we are using > or ≥. Here, we are using ≤ (left), so that means the arrow on the graph should be on a 4, facing left, with a closed circle.

Our answer is B.

Answer:

It will take 47 months ( 3 years and 11 months)

Step-by-step explanation:

We use the compound interest formula here.

Mathematically;

A = P( 1 + r)^t

Where A is the amount which is 2 times the principal here, so we can call it 2P

P is the lump-sum invested

r is the monthly interest rate given as 1.5% = 1.5/100 = 0.015

t = time , which we want to calculate

Substituting these values, we have;

2P = P(1 + 0.015)^t

divide both sides by P

2 = 1.015^t

Take the log of both sides;

log 2 = log (1.015)^t

log 2 = t log 1.015

t = log2/log1.015

t = 46.55

which is approximately 47 months

Answer:

Step-by-step explanation:

Hello, please consider the following.

For x > 1, we can apply Pythagoras theorem as below.

[tex]\text{Let's estimate this sum of two squares.} \\\\(2x)^2+(x^2-1)^2=4x^2+x^4-2x^2+1=x^4+2x^2+1\\\\\text{Let's estimate this square, now.} \\\\(x^2+1)^2=x^4+2x^2+1\\\\\text{The two expressions are equal, meaning.} \\\\(2x)^2+(x^2-1)^2=(x^2+1)^2\\\\\text{Using Pythagoras' theorem, we can say that this is a right triangle.}[/tex]

Thank you

Answer:

[tex]\boxed{x \geq 353}[/tex]

Step-by-step explanation:

Hey there!

Info Given

- Dot is solid

- Line goes to the right

- Dot is at 353

So by using the given info we can conclude that the inequality is,

x ≥ 353

Hope this helps :)

Answer:

Inequality: 100 + 50w ≥ 18000

What to put on graph: w ≥ 358

Answer: Option D. will be the answer.

Explanation: The bowling scores for six persons have been given as 27, 142, 145, 146, 154, 162.

The most appropriate measure of the center of these scores will be the median.

Here median will be mean of 146 and 146 because number of persons are 6 which is an even number.

So there are two center scores those are 145 and 146 and median =  

Option D. will be the answer.

Answer:

48.50 dollars.

Step-by-step explanation:

The collector has a total of 224 coins but 74 of them are 25 cents coins. So, in order to find the number of 20-cent coins we're going to subtract the number of 25-cent coins from the total.

Number of 20-cent coins = 224 - 74 = 150.

Thus, the collector has 150 20-cent coins and 74 25-cent coins for a total of 224 coins.

Now, to know the total value of the collection we need to multiply the value of the coins by the number of coins there are of this value (we are going to do it with the 20-cent and the 25-cent coins) and then sum up our results.

Total value = 74(25) + 150 (20) = 1850 + 3000 = 4850 cents.

So the total value is 4850 cents, we know that each dollar has 100 cents so, to express this number in dollars we are going to divide it by 100 and thus we have that the total value of the collection is 48.50 dollars.

Answer and Step-by-Step explanation:

% increase = 100 x [(new price) - (original price)] / (original price)] = 100 (9.67 - 9.56) / 9.56

% increase ≅ 1.2% (to the nearest tenth)

Answer:

A) 1236 units²

Step-by-step explanation:

Cylinder = 2[tex]\pi[/tex]h+2[tex]\pi[/tex]r²

2(3.14)(7.5)(15)+2(3.14)(7.5x7.5)

706.5+353.25=1059.75

1/2 Sphere = 1/2(4)[tex]\pi[/tex]r²

2(3.14)(7.5)(7.5)

353.25

TOTAL: 1059.75+353.25=1413

HOWEVER...you need to subtract the top of the cylinder ([tex]\pi[/tex]r²) 176.625

1413-176.625=1236.375

So the answer would be A.  (Silo’s do have a bottom, or else the answer would be D)

Answer:

1,236 units²

Step-by-step explanation:

I got it correct on founders edtell and screenshot below as proof

Hi there! :)

Answer:

x = -7.

Step-by-step explanation:

Starting with:

3(2x + 2) = 3x - 15

Begin by distributing '3' with the terms inside of the parenthesis:

3(2x) + 3(2) = 3x - 15

Simplify:

6x + 6 = 3x - 15

Isolate the variable by subtracting '3x' from both sides:

6x - 3x + 6 = 3x - 3x - 15

3x + 6 = -15

Subtract 6 from both sides:

3x + 6 - 6 = -15 - 6

3x = -21

Divide both sides by 3:

3x/3 = -21/3

x = -7.

Answer:

x = -7

Step-by-step explanation:

3(2x+2) = 3x - 15

First, we should simplify on the left side.

6x + 6 = 3x - 15 ; Now we subtract six from both sides.

      -6          -6

6x = 3x - 21 ; next we just subtract 3x from both sides.

-3x   -3x

3x = -21

Finally, we divide 3 from both sides to separate the three from the x.

x = -7

Hope this helps!! <3 :)

Answer

The mean is 8.6

The median is 7

And the mode is 6

Answer:B the amount of money in a bank account never changes.

Step-by-step explanation:

Answer:

B. The amount of money in a bank account never changes.

Step-by-step explanation:

Equilibrium is achieved when the state of a reversible reaction of opposing forces cancel each other out. While in a state of equilibrium, the competing influences are balanced out. Imagine a cup with a hole in it being filled with water from a tap. The level of water in this cup would stay the same if the rate at which the water that flows inside is the same as the water that flows outside. Option B will be the correct answer because the amount of money going into the account is at the same rate of money coming out of the account.

Answer:

Step-by-step explanation:

Since the figure above is a right angled triangle we can use trigonometric ratios to find GV

To find GV we use cosine

cos∅ = adjacent / hypotenuse

From the question

GV is the adjacent

GC is the hypotenuse

So we have

GC = 55°

GV = 55 cos 37

GV = 43.92495

We have the final answer as

Hope this helps you

Answer:

150

Step-by-step explanation:

70% of 500 people are adults and the remainder are children.

There are 150 children

Answer:

32 years old

Step-by-step explanation:

The husband is 32 years old as the wife is 3 years younger than the husband. The son is 3 years older than the daughter. Their family altogether total age today is 68 years while 4 years ago their age total was 54 years. The difference is 14 years. If we divide the difference into 4 then the age can not be whole number which means daughter is born after 2 years. She is now 2 years older. Son is 3 years older than the daughter which means he is 5 years old. The husband then must be 32 years old and wife is 3 years younger which means she is 29 years old now.

32 + 29 + 5 + 2 = 68 years.

Step-by-step explanation:

sin∠M = cos∠N

sin∠M = cos(30°)

sin∠M = √3 / 2

m∠M = 60° or 120°

If ∠M is acute, m∠M = 60°.

Answer: The measure of ∠M is 60°

Step-by-step explanation:

The complement of 30° is 60°

sin∠M =cos∠N

sin∠60°=cos∠30°

the measure of ∠M is 60°

Answer:

=6 units squared

Step-by-step explanation:

area=1/2h(a+b)

        =1/2×2(4+2)

        =6

Answer:

D) 3/2(X-4)

Step-by-step explanation:

Invert and multiply to get:

3(x+4)/2(x²-16)

factor the bottom

3(x+4)/2(x+4)(x-4)

The (x+4)’s cancel out, and you’re left with

3/2(X-4)

[tex]\dfrac{{x+4\over2}}{{x^2-16\over3}}[/tex]

[tex]=\dfrac{3(x+4)}{2(x+4)(x-4)}=\frac{3}{2(x-4)} [/tex]

but in original fraction, denominator can't be zero so we have to exclude x=±4

do that answer is D

Answer:

6

Step-by-step explanation:

Given, 3sin2x−7sinx+2=03sin2⁡x-7sin⁡x+2=0

⇒(3sinx−1)(sinx−2)=0⇒3sin⁡x-1sin⁡x-2=0

⇒sinx=13 or 2⇒sin⁡x=13 or 2

⇒sinx=13    [∵sinx≠2]⇒sin⁡x=13    [∵sin⁡x≠2]

Let  sinα=13,0<α<π2,sinα=13,0<α<π2, then sinx=sinαsinx=sinα

now x=nπ+(−1)nα(n∈I)x=nπ+(−1)nα(n∈I)

⇒x=α,π−α,2π+α,3π−α,4π+α,5π−α⇒x=α,π−α,2π+α,3π−α,4π+α,5π−α Are the solution in [0,5π][0,5π]

Hence, required number of solutions are 6

Answer:

The number to be multiplied is the "multiplicand"

Step-by-step explanation:

a base when it is written in exponential notation

Answer:

125π ft²

Step-by-step explanation:

1/4π(30)² - 1/4π(20)² = 125π

A(t) = 100t^2 + 500t + 625

3,025 square pixels

Answer:

A(t) equals 100t²+ 500t + 625.

The area of the square image after 3 seconds is 3,025 square pixels.

Answer:

d. 19

Step-by-step explanation:

Degrees of freedom is the number is the number of value which is used in the final calculation. It calculate as n-1, where n is the sample size. The degrees of freedom for the given scenario is 19. The sample size is 20 so the degrees of freedom is 1 less which will be 19.

Answer:

integer of course

Step-by-step explanation:

an integer can either be negative or positive.