if sinA=√3-1/2√2,then prove that cos2A=√3/2 prove that

Answers

Answer 1

Answer:

[tex]\boxed{\sf cos2A =\dfrac{\sqrt3}{2}}[/tex]

Step-by-step explanation:

Here we are given that the value of sinA is √3-1/2√2 , and we need to prove that the value of cos2A is √3/2 .

Given :-

• [tex]\sf\implies sinA =\dfrac{\sqrt3-1}{2\sqrt2}[/tex]

To Prove :-

•[tex]\sf\implies cos2A =\dfrac{\sqrt3}{2} [/tex]

Proof :-

We know that ,

[tex]\sf\implies cos2A = 1 - 2sin^2A [/tex]

Therefore , here substituting the value of sinA , we have ,

[tex]\sf\implies cos2A = 1 - 2\bigg( \dfrac{\sqrt3-1}{2\sqrt2}\bigg)^2 [/tex]

Simplify the whole square ,

[tex]\sf\implies cos2A = 1 -2\times \dfrac{ 3 +1-2\sqrt3}{8} [/tex]

Add the numbers in numerator ,

[tex]\sf\implies cos2A = 1-2\times \dfrac{4-2\sqrt3}{8} [/tex]

Multiply it by 2 ,

[tex]\sf\implies cos2A = 1 - \dfrac{ 4-2\sqrt3}{4} [/tex]

Take out 2 common from the numerator ,

[tex]\sf\implies cos2A = 1-\dfrac{2(2-\sqrt3)}{4} [/tex]

Simplify ,

[tex]\sf\implies cos2A = 1 -\dfrac{ 2-\sqrt3}{2}[/tex]

Subtract the numbers ,

[tex]\sf\implies cos2A = \dfrac{ 2-2+\sqrt3}{2} [/tex]

Simplify,

[tex]\sf\implies \boxed{\pink{\sf cos2A =\dfrac{\sqrt3}{2}} } [/tex]

Hence Proved !


Related Questions

4. Cindy purchased a pair of boots which had a sticker price of $85. Cindy paid $5.95 in sales tax. What was the tax rate on Cindy's purchase?

Answers

7%
To get the tax rate just divide 5.95 by 85 and you get 0.07. The. Convert that to a percentage

What is the surface area of the rectangular prism pictured below?
3 meters
9 meters
4 meters

Answers

Answer:

108 meters with the formula lxhxw

Find dy/dx of the function y = √x sec*-1 (√x)​

Answers

Hi there!

[tex]\large\boxed{\frac{dy}{dx} = \frac{1}{2\sqrt{x}}sec^{-1}(\sqrt{x}) + \frac{1}{2|\sqrt{x}|\sqrt{{x} - 1}}}[/tex]

[tex]y = \sqrt{x} * sec^{-1}(-\sqrt{x}})[/tex]

Use the chain rule and multiplication rules to solve:

g(x) * f(x) = f'(x)g(x) + g'(x)f(x)

g(f(x)) = g'(f(x)) * 'f(x))

Thus:

f(x) = √x

g(x) = sec⁻¹ (√x)

[tex]\frac{dy}{dx} = \frac{1}{2\sqrt{x}}sec^{-1}(\sqrt{x}) + \sqrt{x} * \frac{1}{\sqrt{x}\sqrt{\sqrt{x}^{2} - 1}} * \frac{1}{2\sqrt{x}}[/tex]

Simplify:

[tex]\frac{dy}{dx} = \frac{1}{2\sqrt{x}}sec^{-1}(\sqrt{x}) + \sqrt{x} * \frac{1}{2|x|\sqrt{{x} - 1}}[/tex]

[tex]\frac{dy}{dx} = \frac{1}{2\sqrt{x}}sec^{-1}(\sqrt{x}) + \frac{1}{2|\sqrt{x}|\sqrt{{x} - 1}}[/tex]

Answer:

[tex]\displaystyle y' = \frac{arcsec(\sqrt{x})}{2\sqrt{x}} + \frac{1}{2|\sqrt{x}|\sqrt{x - 1}}[/tex]

General Formulas and Concepts:

Algebra I

Exponential Rule [Rewrite]:                                                                           [tex]\displaystyle b^{-m} = \frac{1}{b^m}[/tex]Exponential Rule [Root Rewrite]:                                                                 [tex]\displaystyle \sqrt[n]{x} = x^{\frac{1}{n}}[/tex]

Calculus

Derivatives

Derivative Notation

Basic Power Rule:

f(x) = cxⁿf’(x) = c·nxⁿ⁻¹

Derivative Rule [Product Rule]:                                                                             [tex]\displaystyle \frac{d}{dx} [f(x)g(x)]=f'(x)g(x) + g'(x)f(x)[/tex]

Derivative Rule [Chain Rule]:                                                                                 [tex]\displaystyle \frac{d}{dx}[f(g(x))] =f'(g(x)) \cdot g'(x)[/tex]

Arctrig Derivative:                                                                                                 [tex]\displaystyle \frac{d}{dx}[arcsec(u)] = \frac{u'}{|u|\sqrt{u^2 - 1}}[/tex]

Step-by-step explanation:

Step 1: Define

Identify

[tex]\displaystyle y = \sqrt{x}sec^{-1}(\sqrt{x})[/tex]

Step 2: Differentiate

Rewrite:                                                                                                         [tex]\displaystyle y = \sqrt{x}arcsec(\sqrt{x})[/tex]Product Rule:                                                                                                [tex]\displaystyle y' = \frac{d}{dx}[\sqrt{x}]arcsec(\sqrt{x}) + \sqrt{x}\frac{d}{dx}[arcsec(\sqrt{x})][/tex]Chain Rule:                                                                                                     [tex]\displaystyle y' = \frac{d}{dx}[\sqrt{x}]arcsec(\sqrt{x}) + \bigg[ \sqrt{x}\frac{d}{dx}[arcsec(\sqrt{x})] \cdot \frac{d}{dx}[\sqrt{x}] \bigg][/tex]Rewrite [Exponential Rule - Root Rewrite]:                                                 [tex]\displaystyle y' = \frac{d}{dx}[x^\bigg{\frac{1}{2}}]arcsec(\sqrt{x}) + \bigg[ \sqrt{x}\frac{d}{dx}[arcsec(\sqrt{x})] \cdot \frac{d}{dx}[x^\bigg{\frac{1}{2}}] \bigg][/tex]Basic Power Rule:                                                                                         [tex]\displaystyle y' = \frac{1}{2}x^\bigg{\frac{1}{2} - 1}arcsec(\sqrt{x}) + \bigg[ \sqrt{x}\frac{d}{dx}[arcsec(\sqrt{x})] \cdot \frac{1}{2}x^\bigg{\frac{1}{2} - 1} \bigg][/tex]Simplify:                                                                                                         [tex]\displaystyle y' = \frac{1}{2}x^\bigg{\frac{-1}{2}}arcsec(\sqrt{x}) + \bigg[ \sqrt{x}\frac{d}{dx}[arcsec(\sqrt{x})] \cdot \frac{1}{2}x^\bigg{\frac{-1}{2}} \bigg][/tex]Rewrite [Exponential Rule - Rewrite]:                                                           [tex]\displaystyle y' = \frac{1}{2x^\bigg{\frac{1}{2}}}arcsec(\sqrt{x}) + \bigg[ \sqrt{x}\frac{d}{dx}[arcsec(\sqrt{x})] \cdot \frac{1}{2x^\bigg{\frac{1}{2}}} \bigg][/tex]Rewrite [Exponential Rule - Root Rewrite]:                                                 [tex]\displaystyle y' = \frac{1}{2\sqrt{x}}arcsec(\sqrt{x}) + \bigg[ \sqrt{x}\frac{d}{dx}[arcsec(\sqrt{x})] \cdot \frac{1}{2\sqrt{x}} \bigg][/tex]Arctrig Derivative:                                                                                         [tex]\displaystyle y' = \frac{1}{2\sqrt{x}}arcsec(\sqrt{x}) + \bigg[ \sqrt{x}\frac{1}{|\sqrt{x}|\sqrt{(\sqrt{x})^2 - 1}} \cdot \frac{1}{2\sqrt{x}} \bigg][/tex]Simplify:                                                                                                         [tex]\displaystyle y' = \frac{arcsec(\sqrt{x})}{2\sqrt{x}} + \frac{1}{2|\sqrt{x}|\sqrt{x - 1}}[/tex]

Topic: AP Calculus AB/BC (Calculus I/I + II)

Unit: Derivatives

Book: College Calculus 10e

1. In the spring of 2017, the Consumer Reports National Research Center conducted a survey of 1007 adults to learn about their major health-care concerns. The survey results showed that 574 of the respondents lack confidence they will be able to afford health insurance in the future. Develop a 90% confidence interval for the population proportion of adults who lack confidence they will be able to afford health insurance in the future.

Answers

Answer:

The correct answer is "1668". A further solution is provided below.

Step-by-step explanation:

According to the question,

Estimated proportion,

[tex]\hat{p} = \frac{574}{1007}[/tex]

  [tex]=0.57[/tex]

Margin of error,

E = 0.02

Level of confidence,

= 90%

= 0.90

Critical value,

[tex]Z_{0.10}=1.65[/tex]

Now,

⇒  [tex]0.02=1.65\times \sqrt{\frac{0.57\times 0.43}{n} }[/tex]

 [tex]0.0004=2.7225\times \frac{0.2451}{n}[/tex]

         [tex]n=\frac{2.7225\times 0.2451}{0.0004}[/tex]

             [tex]=1668.21[/tex]

or,

         [tex]n \simeq 1668[/tex]

I WILL GIVE BRAINLIEST FAST

Answers

Answer:

is opposite line BC. Answer is letter E.

At the end of the day, a local bakery sold 83 cakes and had to throw out 7 cakes due to baking errors. Each cake cost the bakery $6.25 to make. The bakery, in turn, sold each cake for $12.75. What was the total profit earned by the bakery today?

Answers

Answer:

The total profit earned by the bakery today was of $495.75.

Step-by-step explanation:

Spending:

83 + 7 = 90 cakes made, each costing 6.25. So

[tex]S = 90*6.25 = 562.5[/tex]

Earnings:

83 cakes sold by $12.75, so:

[tex]E = 83*12.75 = 1058.25[/tex]

Profit:

Earnings subtracted by spending, so:

[tex]P = E - S = 1058.25 - 562.5 = 495.75[/tex]

The total profit earned by the bakery today was of $495.75.

A line that passes through the origin also passes through the point (6,2). What is the slope of the line?

please answer with an explanation

Answers

9514 1404 393

Answer:

  1/3

Step-by-step explanation:

The slope of a line is the ratio of its "rise" to its "run." The "rise" is the change in vertical distance, and the "run" is the corresponding change in horizontal distance between two points on the line. The formula for the slope is ...

  [tex]m=\dfrac{y_2-y_1}{x_2-x_1}\qquad\text{where $(x_1,y_1)$ and $(x_2,y_2)$ are points on the line}[/tex]

In this problem, you are told the line passes through the origin, which is point (x, y) = (0, 0), and through point (6, 2). Using these coordinates in the slope formula gives ...

  [tex]m=\dfrac{2-0}{6-0}=\dfrac{2}{6}=\boxed{\dfrac{1}{3}}[/tex]

__

You may notice that when the line passes through the origin, the slope is simply the ratio y/x of any point on the line. Here, that ratio is 2/6 = 1/3.

_____

Additional comment

A line through the origin is the graph of a proportional relationship. That is, y is proportional to x. The slope of the line is the constant of proportionality. The equation of the line is ...

  y = kx . . . . . . where k is the constant of proportionality.

The line in this problem statement will have the equation ...

  y = (1/3)x

A wiper blade of a car is of length 24 cm sweeping through an angle of begin mathsize 18px style text 120° end text end style. The total area cleaned at one sweep of the blade is​

Answers

Answer:

[tex]A=603.18\ cm^2[/tex]

Step-by-step explanation:

The length of a blade, r = 24 cm

The sweeping angle is 120°.

We need to find the total area cleaned at one sweep of the blade. The area of sector is given by :

[tex]A=\dfrac{\theta}{360}\times \pi r^2[/tex]

[tex]A=\dfrac{120}{360}\times \pi \times 24^2\\\\=603.18\ cm^2[/tex]

So, the total area cleaned at one sweep of the blade is [tex]603.18\ cm^2[/tex].

The CPA Practice Advisor reports that the mean preparation fee for 2017 federal income tax returns was $273. Use this price as the population mean and assume the population standard deviation of preparation fees is $100.A) What is the probability that the mean price for a sample of 30 federal income tax returns is within $16 of the population mean?B) What is the probability that the mean price for a sample of 50 federal income tax returns is within $16 of the population mean?C) What is the probability that the mean price for a sample of 100 federal income tax returns is within $16 of the population mean?D) Which, if any of the sample sizes in part (a), (b), and (c) would you recommend to ensure at least a .95 probability that the same mean is withing $16 of the population mean?

Answers

Answer:

a) 0.6212 = 62.12% probability that the mean price for a sample of 30 federal income tax returns is within $16 of the population mean.

b) 0.7416 = 74.16% probability that the mean price for a sample of 50 federal income tax returns is within $16 of the population mean.

c) 0.8804 = 88.04% probability that the mean price for a sample of 100 federal income tax returns is within $16 of the population mean.

d) None of them ensure, that one which comes closer is a sample size of 100 in option c), to guarantee, we need to keep increasing the sample size.

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

The CPA Practice Advisor reports that the mean preparation fee for 2017 federal income tax returns was $273. Use this price as the population mean and assume the population standard deviation of preparation fees is $100.

This means that [tex]\mu = 273, \sigma = 100[/tex]

A) What is the probability that the mean price for a sample of 30 federal income tax returns is within $16 of the population mean?

Sample of 30 means that [tex]n = 30, s = \frac{100}{\sqrt{30}}[/tex]

The probability is the p-value of Z when X = 273 + 16 = 289 subtracted by the p-value of Z when X = 273 - 16 = 257. So

X = 289

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{289 - 273}{\frac{100}{\sqrt{30}}}[/tex]

[tex]Z = 0.88[/tex]

[tex]Z = 0.88[/tex] has a p-value of 0.8106

X = 257

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{257 - 273}{\frac{100}{\sqrt{30}}}[/tex]

[tex]Z = -0.88[/tex]

[tex]Z = -0.88[/tex] has a p-value of 0.1894

0.8106 - 0.1894 = 0.6212

0.6212 = 62.12% probability that the mean price for a sample of 30 federal income tax returns is within $16 of the population mean.

B) What is the probability that the mean price for a sample of 50 federal income tax returns is within $16 of the population mean?

Sample of 30 means that [tex]n = 50, s = \frac{100}{\sqrt{50}}[/tex]

X = 289

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{289 - 273}{\frac{100}{\sqrt{50}}}[/tex]

[tex]Z = 1.13[/tex]

[tex]Z = 1.13[/tex] has a p-value of 0.8708

X = 257

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{257 - 273}{\frac{100}{\sqrt{50}}}[/tex]

[tex]Z = -1.13[/tex]

[tex]Z = -1.13[/tex] has a p-value of 0.1292

0.8708 - 0.1292 = 0.7416

0.7416 = 74.16% probability that the mean price for a sample of 50 federal income tax returns is within $16 of the population mean.

C) What is the probability that the mean price for a sample of 100 federal income tax returns is within $16 of the population mean?

Sample of 30 means that [tex]n = 100, s = \frac{100}{\sqrt{100}}[/tex]

X = 289

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{289 - 273}{\frac{100}{\sqrt{100}}}[/tex]

[tex]Z = 1.6[/tex]

[tex]Z = 1.6[/tex] has a p-value of 0.9452

X = 257

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{257 - 273}{\frac{100}{\sqrt{100}}}[/tex]

[tex]Z = -1.6[/tex]

[tex]Z = -1.6[/tex] has a p-value of 0.0648

0.9452 - 0.0648 =

0.8804 = 88.04% probability that the mean price for a sample of 100 federal income tax returns is within $16 of the population mean.

D) Which, if any of the sample sizes in part (a), (b), and (c) would you recommend to ensure at least a .95 probability that the same mean is withing $16 of the population mean?

None of them ensure, that one which comes closer is a sample size of 100 in option c), to guarantee, we need to keep increasing the sample size.

C is actually 0.8904

for anybody else stuck on this wondering why cengage is telling you c is wrong

In which quadrant do the points have negative x-coordinates and negative y-coordinates?

Answers

Hi there!  

»»————- ★ ————-««

I believe your answer is:  

Quadrant III

»»————- ★ ————-««  

Here’s why:  

⸻⸻⸻⸻

The plane is split into four quadrants. Quadrant III houses all the points with negative signs for both X and Y values.

⸻⸻⸻⸻

See the attached picture for reference.

⸻⸻⸻⸻

»»————- ★ ————-««  

Hope this helps you. I apologize if it’s incorrect.  

For sure. Quadrant 3

4ab-3a+3bx-2ab anyone know the answer to this problem?

Answers

Answer:

-3a+3bx+2ab

Step-by-step explanation:

PLEASE HELP!!! Choose the best graph that represents the linear equation:
6x = y + 8
Graph A
On a coordinate plane, a line goes through (negative 2, 4) and (0, negative 8).
Graph B
On a coordinate plane, a line goes through (0, negative 8) and (2, 4).
Graph C
On a coordinate plane, a line goes through (negative 2, negative 4) and (0, 8).
Graph D
On a coordinate plane, a line goes through (0, 8) and (2, negative 4).
a.
Graph A
c.
Graph C
b.
Graph B
d.
Graph D



Please select the best answer from the choices provided


A
B
C
D

Answers

Answer:

b.

Graph B

Step-by-step explanation:

We are given the following linear equation:

[tex]6x = y + 8[/tex]

When x = 0:

[tex]6(0) = y + 8[/tex]

[tex]y = -8[/tex]

Thus, the line goes through (0,-8).

When y = 4:

[tex]6x = y + 8[/tex]

[tex]6x = 4 + 8[/tex]

[tex]6x = 12[/tex]

[tex]x = \frac{12}{6} = 2[/tex]

So also through (2,4).

Thus means that the correct answer is given by Graph B.

HELPPPPPPP PLEASEEEEEEE

Answers

Answer:

150 dollars. if I am wrong correct me

Answer:

C and D

Step-by-step explanation:

15 to 30 galons at $9.95 to $21.00

the minimum amount can be found by calculating the minimum amount sold at a minimum price 15*9.95 = $149.25

the maximum amount can be found by calculating the maximum amount sold at a maximum price 30*21 = $630

there are 2 choices that are between 149.25 and 630, C, and D

A box has length 4 feet, width 5 feet, and height 8 inches. Find the volume of the box in cubic feet and in cubic inches.

Answers

Answer:

13.4 cubic feet and 23040 inches

Step-by-step explanation:

Answer:

In cubic feet =  13.3 ft^3 ...........or 13.33ft^3

In cubic inches = 23040in^3

Step-by-step explanation:

In cubic feet it becomes

4(5) = 20 feet ^2   ................but we need volume in feet

so 8 inches = .............2/3 of a foot = 0.666667

Answer therefore is   (4) x (5) x (0.666667) = 13.32ft^3

In cubic inches it becomes

4 x 12 = 48 inches

5  x 12  = 60 inches

and 8 inches

48 x 60 x 8 = 23040 in^3

We check by squaring the divider

23040/12^3 = 13.333

We only square and square again to find a cube but to square once we do this with area too.

Area 1. =  4 x 5 = 20 feet^2

Area 2. =  48 x 60 = 2880 in ^2  / 12^2 = 20

At a sale this week, a sofa is being sold for $117.60. This is a 72% discount from the original price. What is the original price?

Answers

The original price is $420, hope this helps- brainliest if you can please

For its grand opening, a store gives every 12th customer a calendar and every 20th customer a mug. Which guest is the first to receive both a calendar and a mug?​

Answers

Answer: yes

Step-by-step explanation:

The 60th customer as it is the lowest common multiple

Re-write this subtraction as an ADDITION of signed numbers. 7- (-5) =
Now actually compute 7 - (-5) =

Answers

Answer: 12

Step-by-step explanation: Whenever you have a minus a negative in a problem, you can change it to plus a positive.

So we can think of 7 - (-5) as 7 + (+5).

Whenever we have two negatives in a row, we can think of those

negatives as being multiplied together and a negative times a negative

will always result in a positive.

So just add 7 + 5 to get 12.

I’m struggling with this question someone help ASAP plz

Answers

Answer:

The correct answer is:

30 = 10 + 3(h - 2)

        30 = 10 + 3h - 6

        26 = 3h

        h = 8.67

Step-by-step explanation:

We're gonna calculate by our part the hours a new costumer can rent a bike and pay a total of $30, using the original function:

f (h) = 10 + 3(h - 2)

Where:

f (h) = Total cost. h = the number of hours.

We know The total money spent must be $30, by this reason, the function change to:

30 = 10 + 3(h - 2)

Now, we must clear the h variable, by this reason, we multiply 3 by h and 2:

30 = 10 + 3*h - 3*2 30 = 10 + 3h - 6

We pass the 10 and the -6 to the left side of the equality:

30 - 10 + 6 = 3h (Remember to change the signs when you do this step) 26 = 3h

Finally, we pass the 3 to the left side of the equality:

26 / 3 = h (the 3 pass to divide because is multiplying the x)

8.666666666667 = h

If we just use two decimals, the number of hours is:

h = 8.67

How the third option is the one that shows this calculation and result, that is the correct answer.

Mischa wrote the quadratic equation 0=_x2+4x-7 in standard form. If a = -1, what is the value of c in her equation?
C=-7
C= 1
c=4
c=7

Answers

Answer:

A. c = -7

Step-by-step explanation:

Standard form of a quadratic equation is given as ax² + bx + c = 0, where,

a, b, and c are known values not equal to 0,

x is the variable.

Given a quadratic equation of -x² + 4x - 7, therefore,

a = -1

b = 4

c = -7

Calculate the pH of a buffer solution made by mixing 300 mL of 0.2 M acetic acid, CH3COOH, and 200 mL of 0.3 M of its salt sodium acetate, CH3COONa, to make 500 mL of solution. Ka for CH3COOH = 1.76×10–5

Answers

Answer:

Approximately [tex]4.75[/tex].

Step-by-step explanation:

Remark: this approach make use of the fact that in the original solution, the concentration of  [tex]\rm CH_3COOH[/tex] and [tex]\rm CH_3COO^{-}[/tex] are equal.

[tex]{\rm CH_3COOH} \rightleftharpoons {\rm CH_3COO^{-}} + {\rm H^{+}}[/tex]

Since [tex]\rm CH_3COONa[/tex] is a salt soluble in water. Once in water, it would readily ionize to give [tex]\rm CH_3COO^{-}[/tex] and [tex]\rm Na^{+}[/tex] ions.

Assume that the [tex]\rm CH_3COOH[/tex] and [tex]\rm CH_3COO^{-}[/tex] ions in this solution did not disintegrate at all. The solution would contain:

[tex]0.3\; \rm L \times 0.2\; \rm mol \cdot L^{-1} = 0.06\; \rm mol[/tex] of [tex]\rm CH_3COOH[/tex], and

[tex]0.06\; \rm mol[/tex] of [tex]\rm CH_3COO^{-}[/tex] from [tex]0.2\; \rm L \times 0.3\; \rm mol \cdot L^{-1} = 0.06\; \rm mol[/tex] of [tex]\rm CH_3COONa[/tex].

Accordingly, the concentration of [tex]\rm CH_3COOH[/tex] and [tex]\rm CH_3COO^{-}[/tex] would be:

[tex]\begin{aligned} & c({\rm CH_3COOH}) \\ &= \frac{n({\rm CH_3COOH})}{V} \\ &= \frac{0.06\; \rm mol}{0.5\; \rm L} = 0.12\; \rm mol \cdot L^{-1} \end{aligned}[/tex].

[tex]\begin{aligned} & c({\rm CH_3COO^{-}}) \\ &= \frac{n({\rm CH_3COO^{-}})}{V} \\ &= \frac{0.06\; \rm mol}{0.5\; \rm L} = 0.12\; \rm mol \cdot L^{-1} \end{aligned}[/tex].

In other words, in this buffer solution, the initial concentration of the weak acid [tex]\rm CH_3COOH[/tex] is the same as that of its conjugate base, [tex]\rm CH_3COO^{-}[/tex].

Hence, once in equilibrium, the [tex]\rm pH[/tex] of this buffer solution would be the same as the [tex]{\rm pK}_{a}[/tex] of [tex]\rm CH_3COOH[/tex].

Calculate the [tex]{\rm pK}_{a}[/tex] of [tex]\rm CH_3COOH[/tex] from its [tex]{\rm K}_{a}[/tex]:

[tex]\begin{aligned} & {\rm pH}(\text{solution}) \\ &= {\rm pK}_{a} \\ &= -\log_{10}({\rm K}_{a}) \\ &= -\log_{10} (1.76 \times 10^{-5}) \\ &\approx 4.75\end{aligned}[/tex].

What sum is represented by the following number line?

Answers

Answer:

[tex]2\frac{3}{4} +(-4\frac{1}{4} )=-1\frac{2}{4}[/tex]

Step-by-step explanation:

That's the only equation that makes sense to the number line

AB is a diameter of Circle O. Find the measure of BCA

Answers

Answer:

∠ BCA = 90°

Step-by-step explanation:

∠ BCA is an angle in the semicircle and equals 90°

Mrs Lee used 6 Meters of material to make 3 dresses. She used 4 ties as much material for a curtain as for a dress. How much material did she use for the curtain? (Dress)

Answers

Answer:

for each dress she used 6/3 of material

=2

then for a curtain =2x4=8 materials

Which ordered pairs are in the solution set of the system of linear inequalities?

y > Negative one-thirdx + 2

y < 2x + 3

On a coordinate plane, 2 straight lines are shown. The first solid line has a negative slope and goes through (0, 2) and (6, 0. Everything to the right of the line is shaded. The second dashed line has a positive slope and goes through (negative 3, negative 3) and (0, 3). Everything above the line is shaded.

Answers

Options:

(2, 2), (3, 1), (4, 2)

(2, 2), (3, –1), (4, 1)

(2, 2), (1, –2), (0, 2)

(2, 2), (1, 2), (2, 0)

Answer:

A. (2, 2), (3, 1), (4, 2)  

Step-by-step explanation:

Given

[tex]y > -\frac{1}{3}x + 2[/tex]

[tex]y < 2x + 3[/tex]

Required

Solve for x and y

To solve this, we make use of graphical method (see attachment for graph)

All points that lie on the shaded region are true for the inequality

Next, we plot each of the given options on the graph

A. (2, 2), (3, 1), (4, 2)

All 3 points lie on the shaded region.

Hence, (a) is true

Answer:

A. (2, 2), (3, 1), (4, 2)  

Step-by-step explanation:

help me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me me

Answers

Volume of the 3d composite figure is,

(7×6×5)+(7×6×5)/3

= 210+70

= 280 cm³

Relationship between the two volumes,

Volume of the rectangular prism is 3 times the volume of the pyramid.

Answered by GAUTHMATH

Answer:

I was gonna anwer it but somone already did.

Step-by-step explanation:

At a store sales tax is charged at a rate of 2% on the cost price of an item . the sales tax on a dress which cost $180 is

Answers

Answer:

$3.60

Step-by-step explanation:

100% = 180

1% = 180/100 = $1.80

2% = 1%×2 = 1.8×2 = $3.60

An airplane flies 105 miles in ½ hour. How far can it fly in 1 ¼ hours at the same rate of speed?

Answers

Answer:

262.5 miles

Step-by-step explanation:

Correct me if I am wrong

Which problem has a greater (bigger) answer? Solve both, choose the one that has the bigger answer and explain (1-2 sentences) how you found your
answer.
1) (2 + 3) (5 + 5)
2)2 + 3 x 5 + 5 =

Answers

1) 2 • 5 + 3 • 5 + 2 • 5 + 3 • 5 =
= 10 + 15 + 10 + 15 =
= 50


2) 5 • 10 =
= 50

2√m^2 if m is greater than or equal to 0

Answers

Answer:

[tex] \displaystyle \boxed{|2m| }[/tex]

Step-by-step explanation:

we are given that

[tex] \displaystyle 2 \sqrt{ {m}^{2} } [/tex]

since m is greater than or equal to 0 it's a positive number therefore, the square root of m is defined and recall that x²=|x| thus

[tex] \displaystyle \boxed{2 |m|}[/tex]

remember that,|a|•|x|=|ax| hence,

[tex] \displaystyle \boxed{ |2m|}[/tex]

and we're done!

Answer:

2m

Step-by-step explanation:

Given :-

2√m² , m is greater than or equal to 0 .

By question,

→ 2√m²

→ 2 * m

→ 2m

Simplify this math problem show Your work

Answers

9514 1404 393

Answer:

  (p -9q)/(4p² +12pq)

Step-by-step explanation:

The least common denominator will be the product of the denominators.

  [tex]\dfrac{-3}{4p}+\dfrac{1}{p+3q}=\dfrac{-3(p+3q)+1(4p)}{(4p)(p+3q)}=\boxed{\dfrac{p-9q}{4p^2+12pq}}[/tex]

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