let a = {1, 2, 3, 4, , 18} and define a relation r on a as follows: for all x, y ∈ a, x r y ⇔ 4|(x − y).

The probability that a randomly selected child has an IQ above 115 is approximately 0.1056.

You've asked for the probability that a randomly selected child (Ages 6-12) has an IQ above 115, given that children's IQs follow a normal distribution with a mean of 100 and a standard deviation of 12. Here's a step-by-step explanation:

1. Calculate the z-score by using the formula: z = (X - μ) / σ
  Where X = 115 (the IQ value), μ = 100 (mean), and σ = 12 (standard deviation).
  z = (115 - 100) / 12 = 15 / 12 = 1.25

2. Use a standard normal distribution table (also known as a z-table) to find the probability associated with the z-score of 1.25. The table shows that the probability of a z-score being less than 1.25 is approximately 0.8944.

3. Since we need to find the probability of a child having an IQ above 115, we need to find the probability of having a z-score greater than 1.25. This can be calculated as:

1 - P(z ≤ 1.25) = 1 - 0.8944 = 0.1056.

So, the probability that a randomly selected child has an IQ above 115 is approximately 0.1056.

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If two square matrices of order n, namely a and b, have the same determinant (det(a) = det(b)), then the determinant of their product ab, denoted as det(ab), is equal to the determinant of the square of matrix a, denoted as det(a²).

The determinant of a matrix is a scalar value that can be computed using various methods, such as cofactor expansion or row reduction. The determinant of a product of two matrices is equal to the product of their determinants, i.e., det(ab) = det(a) × det(b).

Given that det(a) = det(b), we can substitute this equality into the determinant of the product of a and b, i.e., det(ab) = det(a) × det(b).

Since we are trying to prove that det(ab) = det(a²), we need to find the determinant of a². The square of a matrix a, denoted as a², is the product of matrix a with itself, i.e., a² = a × a.

Using the determinant property for the product of two matrices, we have det(a²) = det(a) × det(a).

Now, substituting det(a) = det(b) into the equation for det(a²), we get det(a²) = det(a) × det(a) = det(a) × det(b).

Comparing this with the earlier equation for det(ab), we see that det(ab) = det(a²), as both equations are equal.

Therefore, we can conclude that if a and b are square matrices of order n, and det(a) = det(b), then the determinant of their product ab, denoted as det(ab), is equal to the determinant of the square of matrix a, denoted as det(a²).

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Brett's claim that AABC is congruent or similar to ADEF is false

Congruence of Triangles: Two triangles are said to be congruent if all three corresponding sides are equal and all  three corresponding angles are equal.

From the given information, we can see that both AABC and ADEF are right triangles because they have one angle that is 90 degrees.  

However, we cannot conclude that AABC and ADEF are congruent (that is, identical in size and shape) because there is not enough information to determine their side lengths and the remaining angles.

Also, we  cannot conclude that AABC and ADEF are similar (ie have the same shape but possibly different sizes) because we only know one pair of corresponding angles (ie right angles) and one pair of corresponding sides (ie AC and DF), which  not enough to show similarity.  Therefore, Brett's claim that AABC is congruent or similar to ADEF is false, and we cannot conclude that AABC-ADEF (ie the difference between these two triangles) is a triangle with well-defined sides and angles.

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The estimated coefficient for the total loans and leases to total assets ratio in terms of the probability of being financially weak is e^9.1732146 = 9866.15. Holding the total expenses/assets ratio constant, a one-unit increase in total loans and leases-to-assets is associated with an increase in the probability of being financially weak by a factor of 9866.15.

In logistic regression, the odds ratio represents the change in the odds of the outcome for a one-unit increase in the predictor variable, holding all other variables constant. To interpret the odds ratio in terms of probability, we can convert the odds ratio to a probability ratio by taking the exponential of coefficient.

In this case, the estimated coefficient for total loans and leases to total assets ratio is 9.1732146, which means that a one-unit increase in this ratio is associated with an increase in the odds of being financially weak by a factor of e^9.1732146 = 9866.15.

This means that the probability of being financially weak increases by approximately 9866 times for a one-unit increase in the total loans and leases to total assets ratio, holding the total expenses/assets ratio constant.

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The solution of the equation m=h²kt²x is t = √(m/h²kx) for t>0.

A value or values which, when substituted for a variable in an equation, makes the equation true is known as a solution.

Also, to solve for some variable in an equation, just isolate that variable on one side of the equation.

To solve for t, we need to isolate it on one side of the equation m=h²kt²x.

We can start by dividing both sides by h²kx:

m/h²kx = t²

To solve for t, we need to take the square root of both sides.

However, we also know that t>0, so we need to take the positive square root:

t = √(m/h²kx)

Therefore, the solution for the indicated variable t is t = √(m/h²kx) for t>0.

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Answer:

$47.82

Step-by-step explanation:

If the price of the jacket is $45 and the sales tax rate in Connecticut is 6.35%, then the total price Megan will need to pay for the jacket including tax is:

$45 + ($45 x 6.35%) = $47.82

To calculate the amount that needs to be on the gift card for Megan to buy the jacket using only the gift card, we simply subtract the total price of the jacket from $0:

$0 - $47.82 = -$47.82

Therefore, Megan needs a gift card with at least $47.82 on it to be able to buy the jacket using only the gift card.

Answer:

To calculate the amount needed on the gift card for Megan to be able to buy the jacket using only the gift card, we need to add the sales tax rate of 6.35% to the price of the jacket.

The price of the jacket is $45, so we can calculate the sales tax by multiplying $45 by 6.35% (0.0635).

$45 * 0.0635 = $2.86

The total cost of the jacket including sales tax is $45 + $2.86 = $47.86.

Therefore, Megan needs a gift card with at least $47.86 on it to buy the jacket using only the gift card.

Step-by-step explanation:

To find the derivative of y, we need to use the power rule and the summation rule for derivatives. The power rule states that if y = cx^n, then y' = ncx^(n-1).

Applying this rule to each term in the summation, we get:

y' = (1*1)x^(1-1) + (2*1)x^(2-1) + (3*1)x^(3-1) + ...

Simplifying this expression, we get:

y' = 1 + 2x + 3x^2 + 4x^3 + ...

Therefore, if y = sum from k=0 to infinity of (k 1)x^(k 3), then y' = 1 + 2x + 3x^2 + 4x^3 + ...

If we have the function y given by the sum from k=0 to infinity of (k+1)x^(k+3), we can find the derivative y' as follows:

y' = d/dx (sum from k=0 to infinity of (k+1)x^(k+3))

To find the derivative, we can differentiate term by term within the sum:

y' = sum from k=0 to infinity of d/dx((k+1)x^(k+3))

Using the power rule for differentiation, we get:

y' = sum from k=0 to infinity of (k+1)(k+3)x^(k+2)

So, the derivative y' is the sum from k=0 to infinity of (k+1)(k+3)x^(k+2).

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To find the correct expression for f(t) given the Laplace transform function f(s) = 320/s^2(s+8), you will need to perform an inverse Laplace transform. The inverse Laplace transform of f(s) is denoted as L^(-1){f(s)} = f(t).

For f(s) = 320/s^2(s+8), you can rewrite it as a sum of partial fractions. After finding the partial fraction decomposition, you can then apply the inverse Laplace transform to each term individually. I highly recommend consulting a table of Laplace transforms for this process.

Once you've applied the inverse Laplace transform to each term, you can sum up the resulting terms to find the final expression for f(t).

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Hydrogen bonding is a unique type of intermolecular force that occurs when a hydrogen atom is bonded directly to a highly electronegative atom such as fluorine, oxygen, or nitrogen.

These highly electronegative atoms have a strong attraction for electrons, which causes the hydrogen bonding atom to take on a partial positive charge. The resulting electrostatic attraction between the positively charged hydrogen atom and the negatively charged atom creates a hydrogen bond.

This type of bonding is responsible for many of the unique properties of water, including its high boiling and melting points, as well as its ability to dissolve a wide range of substances.

Hydrogen bonding is also important in biological processes, such as protein folding and DNA structure. Without hydrogen bonding, many of the structures and functions that we observe in nature would not be possible.

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we would use a one tail test. However, based on the information given in the question, it seems that a two-tail test would be more appropriate.

To determine whether to use a one-tail or two tail test in this scenario, we need to consider the directionality of the hypothesis. If we are simply testing whether the sample mean of visual memory for art majors is different from the population mean, without specifying a direction, then we should use a two-tail test. This is because the alternative hypothesis would be that the sample mean is either significantly higher or significantly lower than the population means. On the other hand, if we had a specific directional hypothesis (e.g. that art majors have better visual memory than the population mean), then we would use a one tail test. However, based on the information given in the question, it seems that a two tail test would be more appropriate.

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A discrete random variable cannot be treated as continuous even when it has a large range of values because they represent distinct, separate values rather than an unbroken range.

Discrete variables are typically expressed as whole numbers, while continuous variables can take on any value within a specified interval.Treating a discrete variable as continuous may lead to inaccuracies and misinterpretation of data. A discrete random variable is characterized by a finite or countably infinite set of possible values, whereas a continuous random variable can take on any value within a given range. Thus, even if a discrete random variable has a large range of values, it cannot be treated as continuous because it can only assume a limited number of specific values.

For example, the number of heads obtained in 10 coin flips is a discrete random variable with possible values ranging from 0 to 10, but it cannot take on non-integer values such as 3.5. In contrast, the time it takes for a car to travel a certain distance is a continuous random variable that can take on any value within a certain range, including non-integer values. Therefore, it is important to distinguish between discrete and continuous random variables in statistical analysis and modeling.

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There are 120 people in a theatre. 72 are female and 48 are male. 12 females purchase an ice cream and 31 males purchase an ice cream.

Frequency trees display the real frequency of certain events. They can display the same data as a two-way table, but frequency trees are more readable since they illustrate the frequency hierarchy. Probability trees depict the likelihood of a series of occurrences.

Solution:

From the question, we can see the there are 120 people in the theatre.

Since, there are 72 females in the theatre we can find the total number of males by 120-72 = 48

Also, the male who purchased Ice Cream were 36 therefore, the males who did not purchased Ice Cream are 48-36 = 12

And, the females who purchased Ice Cream are 41. So, the female who did not purchased Ice Cream are 72 - 41 = 31

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complete question"

there are 120 people in a theatre 72 are female of these 41 purchase an ice cream 36 males purchase and ice cream use this information to compete the frequency tree

Answer:

  (A)  10°

Step-by-step explanation:

You want the measures of the marked angles in the figure showing vertical angles marked (4x-8)° and (2x+1)°.

The angles marked are vertical angles, which means they are congruent.

  4x -8 = 2x +1

  2x -8 = 1 . . . . . . . . subtract 2x

  2x +1 = 10 . . . . . . . add 9

The angle measures are 10°, choice A.

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The solution is : 1 / 13, is the probability that the card chosen is a queen.

Here, we have,

given that,

A card is chosen at random from a standard deck of 52 playing cards.

so, we get,

Total number of cards = 52

Probability of choosing a queen:

In a deck of card there are 4 queens

Probability = 4/52

                  = 1 / 13

Hence, 1 / 13, is the probability that the card chosen is a queen.

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complete question:

A card is chosen at random from a standard deck of 52 playing cards. What is the probability that the card chosen is a queen?

a. The dotplot of the difference (A-P) in time spent online shows that most parents underestimated the amount of time their children spent online during the 6-month period. The majority of the differences are positive, indicating that the actual time spent online was greater than the parents' perception.

b. The mean difference (A-P) in time spent online is (7.1-5.9+5.2-6.2+5.8-4.7+2.5-8.2+3-6.4)/10 = -0.3 hours per day. The standard deviation of the differences can be calculated using a formula or a calculator, and it is approximately 2.82 hours per day. This means that the average difference between the actual time spent online and the parents' perception was a small underestimate of 0.3 hours per day, with a variation of approximately 2.82 hours per day.

c. To construct a 90% confidence interval for the true mean difference (A-P) in time spent online, we can use the formula:

mean difference ± t-value (with 9 degrees of freedom) x (standard deviation / square root of sample size)

Using a t-table, the t-value for a 90% confidence interval with 9 degrees of freedom is approximately 1.83. The standard error of the mean difference is the standard deviation divided by the square root of the sample size, which is 2.82 / sqrt(10) = 0.89. Therefore, the 90% confidence interval for the true mean difference is:

-0.3 ± 1.83 x 0.89

This simplifies to -0.3 ± 1.63, or (-1.93, 1.33) hours per day. This means that we are 90% confident that the true mean difference between the actual time spent online and the parents' perception falls within this interval. Since the interval includes zero, we cannot reject the null hypothesis that there is no difference between the actual time spent online and the parents' perception at the 5% level of significance. However, the interval suggests that there could be a small underestimate or overestimate of the actual time spent online by the parents.

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a. The sample points are the number of houses sold per day, which are: 0, 1, 2, 3, and 4. So there are a total of 5 sample points.

a. There are five sample points, corresponding to the number of houses sold on each of the 200 days.

b. To assign probabilities to the sample points, we need to count how many times each outcome occurred in the 200 days:

c. The probability of not selling any houses on a given day is the same as the probability of 0 houses sold, which is 0.3.

d. To find the probability of selling at least 2 houses, we need to add up the probabilities of selling 2, 3, or 4 houses:

P(selling at least 2 houses) = P(2 houses) + P(3 houses) + P(4 houses)

= 0.2 + 0.08 + 0.02

= 0.3

e. To find the probability of selling 1 or 2 houses, we need to add up the probabilities of selling 1 or 2 houses:

P(selling 1 or 2 houses) = P(1 house) + P(2 houses)

= 0.4 + 0.2

= 0.6

f. To find the probability of selling less than 3 houses, we need to add up the probabilities of selling 0, 1, or 2 houses:

P(selling less than 3 houses) = P(0 houses) + P(1 house) + P(2 houses)

= 0.3 + 0.4 + 0.2

= 0.9

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In order to double the error margin, the new sample size should be four times smaller than the original sample size. Therefore, the correct answer is: C. One-fourth of the original sample size.

To determine how big of a sample size should be used to double the error margin compared to the original sample size, we need to understand the relationship between error margin, sample size, and original sample size.

Error margin is inversely proportional to the square root of the sample size. This means that when you increase the sample size, the error margin decreases, and vice versa. The formula for this relationship is:

Error Margin = Constant / √(Sample Size)

To double the error margin, we can set up the following equation:
2 * (Constant / √(Original Sample Size)) = Constant / √(New Sample Size)

Now, we can solve for the New Sample Size:
2 * √(Original Sample Size) = √(New Sample Size)

Square both sides of the equation:
4 * Original Sample Size = New Sample Size

Based on this equation, the new sample size should be four times smaller than the original sample size. Therefore, the correct answer is One-fourth of the original sample size.

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The bubble sort algorithm applied to the list of 6, 2, 3, 1, 5, 4 is as follows:

Step 1: 6, 2, 3, 1, 5, 4

Step 2: 2, 6, 3, 1, 5, 4

Step 3: 2, 3, 6, 1, 5, 4

Step 4: 2, 3, 1, 6, 5, 4

Step 5: 2, 3, 1, 5, 6, 4

Step 6: 2, 3, 1, 5, 4, 6

Bubble Sort is an algorithm that consists of repeatedly swapping adjacent elements if they are in wrong order. This algorithm is also known as Sinking Sort.

Bubble Sort works by comparing each element of the list with the adjacent element and swapping them if they are in wrong order. The algorithm continues this process until the list is sorted.

The bubble sort algorithm applied to the list of 6, 2, 3, 1, 5, 4 is as follows:

Step 1: 6, 2, 3, 1, 5, 4

Step 2: 2, 6, 3, 1, 5, 4

Step 3: 2, 3, 6, 1, 5, 4

Step 4: 2, 3, 1, 6, 5, 4

Step 5: 2, 3, 1, 5, 6, 4

Step 6: 2, 3, 1, 5, 4, 6

After the first pass, the largest element will be at the end of the list. After the second pass, the second largest element will be at the end of the list, and so on.

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The given statement, "smoothing parameter (alpha) close to 1 gives more weight or influence to recent observations over the forecast" is true.

The smoothing parameter (alpha) defines the weight or impact given to the most recent observation in the forecast when we apply a smoothing approach such as Simple Exponential Smoothing. If alpha is near to one, we are assigning greater weight or influence to the most recent observation, which makes the forecast more sensitive to changes in the data. In other words, an alpha value near one indicates that we are depending on current data to estimate future values.

If alpha is near zero, the forecast will be less sensitive to changes in the data and will depend more largely on previous observations. This is because we are giving equal weight or influence to all observations, regardless of when they occurred.

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The value of x when y=0 from the given absolute value equation is,

⇒ x = -1.

Here, The graph for the absolute equation y=|x+2| - 1 is given.

Now, Rewrite in vertex form and use this form to find the vertex (h,k).

(-2, -1)

To find the x-intercept, substitute in 0 for y and solve for x.

To find the y-intercept, substitute in 0 for x and solve for y.

x-intercept(s): (-1,0),(-3,0)

y-intercept(s): (0, 1)

Here, y>0

So, 1 = |x+2|-1

2=x+2

x=0

When y<0

So, -1=|x+2|-1

x+2=0

x=-1

When y=0

0=|x+2|-1

1=x+2

x=-1

Therefore, the value of x when y=0 from the given absolute value equation is x=-1.

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The statement, "alternative hypothesis is the hypo-thesis that an "analyst" is trying to prove" is True, because it is the hypothesis that an analyst is trying to prove through their research.

The "Alternative-hypothesis" is defined as the hypothesis which an analyst is trying to prove or support through their research or analysis.

It is the opposite of the "null-hypothesis", and it suggests the presence of a relationship or effect between variables being studied.

In statistical hypothesis testing, the analyst generally formulates both a "null-hypothesis" and an "alternative-hypothesis", and collects data to determine which hypothesis is supported by the evidence.

Therefore, the statement is True.

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The given question is incomplete, the complete question is

The alternative hypothesis is the hypothesis that an analyst is trying to prove. True or False

1. The angle θ with the same sine function value as 260° is θ = 100°.

2. The angle θ with the same sine and cosine function values as 260° is θ = 100°.

1. Sine function: To find the angle with the same sine function value as 260°, we can use the property sin(180° - x) = sin(x), where x is the angle we're looking for. Since 260° > 180°, let's first find the difference between 260° and 180°:

260° - 180° = 80°

Now, we can use the property mentioned above:

sin(180° - 80°) = sin(100°)

So, the angle θ with the same sine function value as 260° is θ = 100°.

2. Cosine function: To find the angle with the same cosine function value as 260°, we can use the property cos(360° - x) = cos(x), where x is the angle we're looking for. Let's find the difference between 360° and 260°:

360° - 260° = 100°

Now, we can use the property mentioned above:

cos(360° - 100°) = cos(260°)

So, the angle θ with the same cosine function value as 260° is θ = 100°.

Therefore, the angle θ with the same sine and cosine function values as 260° is θ = 100°.

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Answer:

BC/CD = DE/EF

The slope of this line is 2/3. From B, go up two units to C, then right three units to D.

The average speed is 10.63 mi/hr. By MVT, the speed was exactly 10.63 mi/hr at least twice. By the intermediate value theorem, the speed between 0 and 0 mi/hr was constant. Therefore, the speed of 10 mi/hr was reached at least twice in the race. The correct answer is A.

The average speed is (6.2 mi)/(35/60 hr) = 10.63 mi/hr.

By the Mean Value Theorem (MVT), there must exist a time during the race when the runner's instantaneous speed was equal to the average speed, i.e., 10.63 mi/hr.

By the Intermediate Value Theorem (IVT), since the runner started at 0 mi/hr and finished at 0 mi/hr, there must be some continuous segment of the race where the runner's instantaneous speed was exactly 10 mi/hr. Since the average speed is greater than 10 mi/hr, this segment must occur at least twice.

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A sample size of at least 150 is needed to achieve a 98% confidence interval with a margin of error of ±55 vehicles per hour.

We can use the t-distribution to construct a confidence interval for the population mean improvement in traffic flow. With a sample size of 50, the degrees of freedom are 50 - 1 = 49. Using a 95% confidence level, the critical value of t is 2.009. Therefore, the 95% confidence interval is:

653.5 ± 2.009 * (311.7 / sqrt(50))

= 653.5 ± 89.09

= (564.41, 742.59)

So, the 95% confidence interval for the improvement in traffic flow is (564.41, 742.59) vehicles per hour.

Using a 98% confidence level, the critical value of t for 49 degrees of freedom is 2.681. Therefore, the 98% confidence interval is:

653.5 ± 2.681 * (311.7 / sqrt(50))

= 653.5 ± 119.66

= (533.84, 773.16)

So, the 98% confidence interval for the improvement in traffic flow is (533.84, 773.16) vehicles per hour.

To find the necessary sample size, we can use the formula:

n = (z * σ / E)^2

where z is the critical value of the standard normal distribution, σ is the standard deviation of the sample, and E is the margin of error. For a 95% confidence interval with a margin of error of ±55, the value of z is 1.96. Substituting the given values, we get:

n = (1.96 * 311.7 / 55)^2

= 97.22

So, a sample size of at least 98 is needed to achieve a 95% confidence interval with a margin of error of ±55 vehicles per hour.

Using a 98% confidence level and a margin of error of ±55, the value of z is 2.33. Substituting the given values, we get:

n = (2.33 * 311.7 / 55)^2

= 149.33

So, a sample size of at least 150 is needed to achieve a 98% confidence interval with a margin of error of ±55 vehicles per hour.

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The simulation that could be used to fairly represent the situation is A. Use a computer to randomly generate 4 numbers from 1 to 3. Each time 1 appears, it represents a strawberry taffy.

The probability of each taffy being strawberry is 0.25, so the probability of all 3 taffies being strawberry is:

0.25 * 0.25 * 0.25 = 0.015625 or approximately 1.56%

Therefore, the likelihood of all taffies being strawberry is very low.

The simulation that could be used to fairly represent the situation is to use a computer to randomly generate 4 numbers from 1 to 3. Each time 1 appears, it represents a strawberry taffy. This simulates the probability of each taffy being strawberry being 0.25 or 25%.

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There is precisely one local minimum point in the two-dimensional space of function f(x,y), and it is located at the critical point (1,1).

To find the local minimum points of f(x,y) in R², we need to find the critical points where the gradient of f is zero or does not exist,

and then test these points using the second partial derivative test or another appropriate method to determine whether they are local minima, maxima, or saddle points.

The gradient of f(x,y) is given by:

∇f(x,y) = (y - y², x - x²)

To find the critical points, we need to solve the system of equations:

This gives us two possible critical points: (0,0) and (1,1).

To test these points, we can use the second partial derivative test.

The Hessian matrix of f is:

Evaluating the Hessian matrix at each critical point gives:

which has eigenvalues λ1 = -1 and λ2 = 1, indicating a saddle point.

which has eigenvalues λ1 = λ2 = -1, indicating a local maximum.

Therefore, f(x,y) has exactly one local minimum point in R², at the critical point (1,1).

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