Photo math said the answer was 2x but I’m not sure

Substitute y = tan(x) and dy = sec²(x) dx to transform the integral to

[tex]\displaystyle \int_0^{\frac\pi2} \cot(x) \ln(\sec(x)) \, dx = \frac12 \int_0^\infty \frac{\ln(1+y^2)}{y(1+y^2)} \, dy[/tex]

and we split the integral at y = 1.

Examining the one over [0, 1], expand into partial fractions :

[tex]\dfrac1{y(1+y^2)} = \dfrac1y - \dfrac y{1+y^2}[/tex]

Then

[tex]\displaystyle \int_0^1 \frac{\ln(1+y^2)}{y(1+y^2)} \, dy = \int_0^1 \frac{\ln(1+y^2)}y \, dy - \int_0^1 \frac{y \ln(1+y^2)}{1 + y^2} \, dy[/tex]

In the integral over [1, ∞), substitute y = 1/z :

[tex]\displaystyle \int_1^\infty \frac{\ln(1+y^2)}{y(1+y^2)} \, dy = \int_0^1 \frac{z \ln\left(1+\frac1{z^2}\right)}{1+z^2} \, dz \\\\ = \int_0^1 \frac{z \ln\left(1+z^2\right)}{1+z^2} \, dz - 2 \int_0^1 \frac{z \ln(z)}{1+z^2} \, dz[/tex]

Some terms cancel and we're left with

[tex]\displaystyle \int_0^\infty \frac{\ln(1+y^2)}{y(1+y^2)} \, dy = \frac12 \int_0^1 \frac{\ln(1+y^2)}y \, dy - \int_0^1 \frac{y \ln(y)}{1+y^2} \, dy[/tex]

Use the series expansions of ln(1 + y) and 1/(1 - y) - both are valid for |y| < 1.

[tex]\displaystyle \int_0^1 \frac{\ln(1+y^2)}y \, dy = - \sum_{n=1}^\infty \frac{(-1)^n}n \int_0^1 y^{2n-1} \, dy = -\frac12 \sum_{n=1}^\infty \frac{(-1)^n}{n^2} = \frac{\pi^2}{24}[/tex]

[tex]\displaystyle \int_0^1 \frac{y \ln(y)}{1+y^2} \, dy = \sum_{n=0}^\infty (-1)^n \int_0^1 y^{2n+1} \ln(y) \, dy = -\frac14 \sum_{n=0}^\infty \frac{(-1)^n}{(n+1)^2} = -\frac{\pi^2}{48}[/tex]

Putting everything together, we have

[tex]\displaystyle \int_0^{\frac\pi2} \cot(x) \ln(\sec(x)) \, dx = \frac12\times\frac{\pi^2}{24} - \left(- \frac{\pi^2}{48}\right) = \boxed{\frac{\pi^2}{24}}[/tex]

Complete question is;

Researchers from the Educational Testing Service (ETS) found that providing immediate feedback to students answering openended questions can dramatically improve students’ future performance on exams (Educational and Psychological Measurement, Feb. 2010). The ETS researchers used questions from the Graduate Record Examination (GRE) in the experiment. After obtaining feedback, students could revise their answers. Consider one of these questions. Initially, 50% of the students answered the question correctly. After providing immediate feedback to students who answered incorrectly, 70% answered correctly. Consider a bank of 100 open-ended questions similar to those on the GRE. a. In a random sample of 20 students, what is the probability that more than half initially answer the question correctly? b. Refer to part a . After providing immediate feedback, what is the probability that more than half of the students answer the question correctly?

Answer:

A) 41.2%

B) 95.2%

Step-by-step explanation:

This is a binomial probability distribution problem, so we will use the formula;

P(k) = (n!/(k!(n - k)!) × p^(k) × (1 - p)^(n-k)

A) Initially, 50% of the students answered the question correctly.

Thus, p = 0.5

Also,n = 20

Now, the probability that more than half initially answer the question correctly would be:

P(k > 10)

This can be expressed as;

P(k > 10) = P(11) + P(12) + P(13) + P(14) + P(15) + P(16) + P(17) + P(18) + P(19) + P(20)

P(11) = (20!/(11!(20 - 11)!) × 0.5^(11) × (1 - 0.5)^(20-11) = 0.1602

Similarly,

P(12) = (20!/(12!(20 - 12)!) × 0.5^(12) × (1 - 0.5)^(20-12) = 0.1201

P(13) = (20!/(13!(20 - 13)!) × 0.5^(13) × (1 - 0.5)^(20-13) = 0.0739

Using online binomial probability calculator we can get the remaining values which are;

P(14) = 0.037

P(15) = 0.0148

P(16) = 0.0046

P(17) = 0.0011

P(18) = 0.0002

P(19) = 0.00002

P(20) = 0

Thus;

P(k > 10) = 0.1602 + 0.1201 + 0.0739 + 0.037 + 0.0148 + 0.0046 + 0.0011 + 0.0002 + 0.00002 + 0 ≈ 0.41192 = 41.2%

B) After providing immediate feedback, we are told that 70% answered correctly.

Thus; p = 70% = 0.7

Similar to A above and using online binomial probability calculator, we have;

P(11) = 0.0654

P(12) = 0.1144

P(13) = 0.1643

P(14) = 0.1916

P(15) = 0.1789

P(16) = 0.1304

P(17) = 0.0716

P(18) = 0.0278

P(19) = 0.0068

P(20) = 0.0008

Thus;

P(k > 10) = 0.0654 + 0.1144 + 0.1643 + 0.1916 + 0.1789 + 0.1304 + 0.0716 + 0.0278 + 0.0068 + 0.0008 = 0.952 = 95.2%

Answer:

he Formula h = -16t^2 + vt + s; where

h = height after t seconds

t = time in seconds

v = upward velocity

s = initial height (t=0)

also note that

-16t^2 represents the downward force of gravity for t seconds

+vt = the upward force for t seconds

:

the height when he hits the water = 0 therefore:

0 = -16t^2 + 8t + 24

usually written

-16t^2 + 8t + 24 = 0

we can simplify this, divide by -8, then we have

2t^2 - t - 3 = 0

this will factor to

(2t - 3)(t + 1) = 0

the positive solution

2t = 3

t = 3/2

t = 1.5 seconds to hit the water

-

Form the actual equation

Find vertex as vertex is maximum

x coordinate

y coordinate

Max height is 25m

Time to reach is 0.25s

Answer:

B. (3x-12)+5/x

Step-by-step explanation:

Difference means - or minus

Three times a number x and 12= 3x-12

Increased= + or plus

quotient= / or divide

5 and the number x= 5/x

So the answer is,

(3x-12)+5/x

I hope you understand.

Answer:

31-32

Hyposis: SHe is the mother.

Conclusion: She's not.

Step-by-step explanation:

Answer:

If your question is set up like this [tex]\sqrt{6x^2-8}=-8x[/tex] then your answer is No solution.

If your question is set up like this[tex]\sqrt{6x^2}-8=-8x[/tex] then your answer is [tex]x=\frac{4(8-\sqrt{6}) }{29}[/tex] or x = 0.765

Hope this helps!

D. 2 4/9

Note: the symbol on top of 4 - means that the number is recurring/repeating infinitely.

Answer:  (D) just did the unit test review on edge

Step-by-step explanation:

Answer:

j(x) matches #3

g(x) matches #2

f(x) matches #4

h(x) matches #1

Answer:

14.28

Step-by-step explanation:

2% of 14 is .28

.28 + 14 = 14.28

Hi!

Since the price was decreased by 2%, that means that 14 is 98% (100% - 2%) of the original price. So, we just have to figure out 98% of what number is 14.

98% can be written in decimal form as 0.98.

We can set up the following equation:

14 = 0.98x

Now, divide both sides by 0.98:

14/0.98 = 14.2857143

The question says to round to the nearest penny, so your answer is

It will take them 20 minutes to do the job working together.

Given that Pete can do a job in 50 minutes while his brother Jim can do it in 1/2 the time, to determine how long it will take them to do the job working together, the following calculation must be performed:

Therefore, it will take them 20 minutes to do the job working together.

Learn more about working time calculation in https://brainly.com/question/536439

Solution:

the percent markdown of the iPad is 17.86%

Given:

Original Price = $700

Final price = $575

The markdown is gotten by;

[tex]Markdown=original~price-final~price[/tex]

[tex]Markdown=700-575[/tex]

Markdown = $125

Thus, the percent markdown is gotten by;

[tex]percent~markdown=\frac{markdown}{original~price}~x~ 100[/tex]

percent markdown = [tex]\frac{125}{700}[/tex] × 100%

percent markdown =[tex]\frac{12500}{700}[/tex]

percent markdown = 17.857 %

percent markdown  ≈ 17.86%

Therefore, the percent markdown of the iPad is 17.86%

Hope this helps!!

If you have any questions please ask.

Answer:

It would be neither.

Step-by-step explanation:

It definitely is not parallel since Line 1 would run into Line 2 at (4, 1). Nor could it be perpendicular because they do run into each other but do not make a 90 degree angle.

9514 1404 393

Answer:

  18050 square feet

Step-by-step explanation:

Let x represent the length of fence parallel to the creek. Then the remaining 380-x feet of fence is divided between the two ends of the pasture. The area will be the product ...

  A = (x)(1/2)(380 -x)

The graph of this is a parabola that opens downward. It has x-intercepts at x=0 and x=380. The vertex (maximum) will be on the line of symmetry, halfway between these zeros, at x = (0 +380)/2 = 190.

Then the area is ...

  A = (190 ft)(1/2)(380 -190 ft) = (190 ft²)/2 = 18,050 ft²

The maximum possible area of the pasture is 18,050 square feet.

16 portions

explanation:

12 / 3/4

   = 12 * 4/3 

= 4*4 = 16

Answer:

23/24

Step-by-step explanation:

To find the total distance of Sunday and Saturday we add 5/8 + 1/3

= 5/8 + 1/3

= 5 × 3/8 × 3 + 1 × 8/3 × 8

= 15/24 + 8/24

= 15 + 8/ 24

= 23/24

Answer:

c

Step-by-step explanation:

Answer:

~c~

Step-by-step explanation:

Answer:

  9

Step-by-step explanation:

The product of the secant lengths BC and BD is equal to the square of the tangent length BA.

  BC×BD = BA²

  3×(3 +x) = 6²

  3 +x = 12 . . . . . divide by 3

  x = 9 . . . . . . subtract 3

_____

Additional comment

Sometimes the relationships involving secants, tangents, and chords can be difficult to remember. There is basically one rule that applies to all of these geometries:

  the product of segment lengths to the circle from the point of intersection of the secants/tangents/chords is the same

A tangent can be thought of as a secant that has a length of 0 between its end points. That is, the two lengths from the point of intersection to the circle are the same.

Here is an example of this rule applied to chords:

https://brainly.com/question/27160911

Answer:

You would use lbs.

Step-by-step explanation:

mm is a unit of distance.

Oz is too small of a unit for weight.

lbs are just right!

Solution:

Given:

Substitute the value of x into the expression.

[tex]5\sqrt{x - 1} + 9[/tex]

[tex]\rightarrow 5\sqrt{10 - 1} + 9[/tex]

Simplify the root:

[tex]\rightarrow5\sqrt{9} + 9[/tex]

[tex]\rightarrow(5 \times \sqrt{9}) + 9[/tex]

[tex]\rightarrow(5 \times 3) + 9[/tex]

Multiply 5 and 3:

[tex]\rightarrow15 + 9[/tex]

Add 15 and 9:

[tex]\rightarrow24[/tex]

Answer:

Options A & C are False while Options B & D are true.

Step-by-step explanation:

The definition of least squares regression line is given as;

The Least Squares Regression Line is a line that normally causes the vertical distance from the data points to the regression line to be as small as possible.

The term “least squares” is derived from the fact that the best line of fit is one that minimizes the the sum of squares of the errors which is also called the variance.

From this definition above, we can see that options A and C are false while option B is the perfect definition for the least line of squares.

Now, the point (x-bar,y-bar ) is known as the mean.

However, every least squares must pass through the middle point of the given data. The mean is the middle point of data in regression analysis. Thus, we can infer that the least-squares regression line always passes through the mean which is point (x-bar,y-bar ). Thus, option D is true.

Answer:

b = 3

Step-by-step explanation:

(2,5) is information! x = 2 and y = 5.

Use these values in the equation:

y = x + b

5 = 2 + b

Subtract 2.

3 = b

The equation of the line is y = x + 3.

Answer:

[tex]x \: intercept = ( \frac{5}{2} ,0) \\ y \: intercept = (0, \frac{5}{3} )[/tex]

Step-by-step explanation:

STEP 1: Define x and y intercepts

The x-intercept is where a line crosses the x-axis, and the y-intercept is the point where the line crosses the y-axis.

Step 2: We plot the graph of the given function

The graph can be seen in the graph image I sent. The x and y intercepts are also identified.

Explanation:

Any parallelogram has two pairs of opposite sides that are parallel.

A rectangle is a parallelogram, but not the other way around.

Choices A and B are trapezoids with exactly one pair of parallel sides.

Answer:

exact form: -16/3

decimal form: -5.3

mixed number form: -5 1/3

Step-by-step explanation:

solve for x by simplifying both sides of the equation, then isolating the variable.

3/4X + 2 = 3/8X

3/4X - 3/8X = - 2

(3/4 - 3/8)X = -2

((6-3)/8)X =-2

3/8X = -2

3X = (-2)(8)

3X = -16

X = -16/3

3x⁴ = 3x³ • x, and

3x³ (x - 2) = 3x⁴ - 6x³

Subtract this from the numerator to get a remainder of

(3x⁴ - 8x³ - x² + 9x + 5) - (3x⁴ - 6x³) = -2x³ - x² + 9x + 5

-2x³ = -2x² • x, and

-2x² (x - 2) = -2x³ + 4x²

Subtract this from the previous remainder to get a new remainder of

(-2x³ - x² + 9x + 5) - (-2x³ + 4x²) = -5x² + 9x + 5

-5x² = -5x • x, and

-5x (x - 2) = -5x² + 10x

Subtract this from the last remainder to get a new one of

(-5x² + 9x + 5) - (-5x² + 10x) = -x + 5

-x = -1 • x, and

-1 (x - 2) = -x + 2

This gives a new remainder of

(-x + 5) - (-x + 2) = 3

3 does not divide x, so we're done.

So, we have

(3x⁴ - 8x³ - x² + 9x + 5) / (x - 2) = 3x³ - 2x² - 5x - 1 + 3/(x - 2)

Answer:

[tex]\sf\fbox\red{Answer:-}[/tex]

gud noon!

dopamine is responsible for how we feel pleasure

[tex]\small\fbox{\blue{\underline{mαrk \; mє \; вrαínlíєѕt \; plєαѕє ♥}}}[/tex]

Answer:

18.98°

Step-by-step explanation:

1) p=arcsin(13/40);

2) p=arcsin0.325≈18.98°.