3. Andre and Elena are saving money. Andre starts with $50 in his savings account and adds $5 per week. Elena starts with $5 in her savings account and adds $10 each week. a. After four weeks, who has more money in their savings account? Explain how you

Answer:

-----------------

Given the quadratic equation:

Solve it in the following steps:

So the solution is: {- 3/2; 1/3}

The y-intercept of Jacob's graph representing the relationship between time and money is $60. If Jacob doesn't deposit any additional money into the account, he will have $79.49 in eight years, rounded to the nearest cent.

In the given equation, 60(1 + 0.04)x, the initial deposit of $60 is represented by the coefficient 60. The term (1 + 0.04) represents the factor by which the initial amount is multiplied each year, accounting for the 4% interest rate. The variable x represents the number of years.

The y-intercept of the graph represents the initial amount of money when x (the number of years) is 0. In this case, when Jacob hasn't invested for any years yet, his balance is the initial deposit of $60. Therefore, the y-intercept of Jacob's graph is $60.

To calculate the amount of money Jacob will have in eight years without any additional deposits, we can substitute x = 8 into the equation. The calculation would be 60(1 + 0.04)8. Evaluating this expression yields approximately $79.49. Rounding to the nearest cent, Jacob will have $79.49 in eight years without making any additional deposits.

In summary, the y-intercept of Jacob's graph is $60, and if he doesn't deposit any more money, he will have $79.49 in eight years.

Learn more about initial deposit  here :

https://brainly.com/question/21845455

#SPJ11

Answer: 45 degrees

Step-by-step explanation: Over 5 on the x-axis and whatever point is above it on the y-axis which would be 45

Any elementary row operation on A can be expressed as a product of replacement operations on A. This means that A can be row reduced to U using only replacement operations, which is the converse of what was proved in the text.

The LU factorization of a matrix A involves decomposing it into a lower triangular matrix L and an upper triangular matrix U, such that A = LU. This means that A can be written as the product of two triangular matrices, one of which is lower triangular and the other is upper triangular.

To show that A can be row reduced to U using only replacement operations, we need to prove that any elementary row operation performed on A can be expressed as a product of replacement operations on A.

First, consider the operation of multiplying a row of A by a scalar. This is a replacement operation, since it replaces one row of A with a multiple of itself.

Next, consider the operation of adding a multiple of one row of A to another row. This is also a replacement operation, since it replaces one row of A with a linear combination of itself and another row.

Finally, consider the operation of interchanging two rows of A. This can be expressed as a sequence of replacement operations: first, add one row to the other, then subtract the original row from the first row, and finally add the second row back to the first row.

To know more about LU factorization, refer to the link below:

https://brainly.com/question/30466122#

#SPJ11

Answer:

30 yards:6 inches = 5 yards per inch

(5 yards/inch)(2 inches) = 10 yards

The actual length of the east side is 10 yards.

The value of x is 4.

Since, △ABC≅ △EDF

We know by the property of Congruence

AB = DF

CB = DE

AC = FE

and, <A = <F, <B = <D, <C = <E

So, <A = <F

3x + 3=  5x - 7

3x - 5x = -7 - 3

-2x = -8

x = 4

Thus, the value of x is 4.

Learn more about Congruency here:

https://brainly.com/question/31992651

#SPJ1

The probability of rolling a 1 on the first roll and a 6 on the second roll is 1/36.

Since each roll is independent of the other, the probability of the first roll being a 1 and the second roll being a 6 is the product of the probabilities of each event happening separately.

The probability of rolling a 1 on the first roll is 1/6, and the probability of rolling a 6 on the second roll is also 1/6. Therefore, the probability of both events occurring is:

1/6 × 1/6 = 1/36

So the probability of rolling a 1 on the first roll and a 6 on the second roll is 1/36.

To know more about probability refer here:

https://brainly.com/question/11234923

#SPJ11

Answer:

Step-by-step explanation:

Step-by-step explanation:

Firstly, let's get the fractions out of mixed form.

2 1/5 = 11/5

(To do this, multiply 2 times 5 and add to the 1.)

1 5/6 = 11/6

(To do this, multiply 1 times 6 and add to the 5.)

Next, let's get the common denominator. When making a common denominator, keep in mind you must multiply/divide both the numerator and denominator

The absolute maximum value of h(x) over the interval [-3,3] is 4.

To find the absolute maximum value, we need to look at the critical points and the endpoints of the interval. Taking the derivative of h(x) and setting it equal to 0, we get 4x-1=0. Solving for x, we get x=1/4.

Plugging this value into h(x), we get h(1/4)=-15/8. However, this is not within the interval [-3,3], so we need to evaluate h(-3), h(3), and h(1/4). We find that h(-3)=10, h(3)=-16, and h(1/4)=-15/8.

Therefore, the absolute maximum value of h(x) over the interval [-3,3] is 4, which occurs at x=-1/2.

To know more about critical points click on below link:

https://brainly.com/question/31017064#

#SPJ11

Therefore, the population increases by 3516 cattle between the 5th and 9th years.

To find the population increase between the 5th and 9th years, we need to calculate the integral of the given rate function (400 + 80t) with respect to t from 5 to 9.
Step 1: Find the integral of the rate function.
∫(400 + 80t) dt = 400t + 40t^2 + C
Step 2: Calculate the population increase at t = 5 and t = 9.
For t = 5: 400(5) + 40(5^2) = 2000 + 1000 = 3000
For t = 9: 400(9) + 40(9^2) = 3600 + 2916 = 6516
Step 3: Find the difference between these two values.
Total increase = 6516 - 3000 = 3516

Therefore, the population increases by 3516 cattle between the 5th and 9th years.

To know more about function visit :

https://brainly.com/question/11624077

#SPJ11

The line integral of the function f(x,y) = x²y³ -√x along the curve C, which is the arc of the curve y = √x from (0,0) to (4,2), has a value of -88/45.

To evaluate the line integral ∫C(x²y³ - √x) dy, where C is the arc of the curve y = √x from (0,0) to (4,2), we need to parameterize the curve and substitute the values into the integrand.

Let's parameterize the curve as x = t² and y = t, where t varies from 0 to 2. Then, dx/dt = 2t and dy/dt = 1.

Substituting these values into the integrand, we get:

(x²y³ - √x) dy = (t⁴t³ - t√t)dt

Integrating from t = 0 to t = 2, we get:

∫C(x²y³ - √x)dy = ∫0²(t⁷/2 - t³/²)dt

Evaluating this integral, we get:

Therefore, the value of the line integral is -88/45.

Learn more about line integral

brainly.com/question/29850528

#SPJ11

Answer:

To determine the coordinates of the intercepts with the axes, we need to find the points where a graph intersects the x-axis (x-intercept) and the y-axis (y-intercept).

X-Intercept:

To find the x-intercept, we set y = 0 and solve for x. This means we are looking for the point(s) where the graph crosses the x-axis.

Y-Intercept:

To find the y-intercept, we set x = 0 and solve for y. This means we are looking for the point(s) where the graph crosses the y-axis.

Let's work through an example to illustrate this process:

Suppose we have an equation of a line: y = 2x + 3.

X-Intercept:

Setting y = 0:

0 = 2x + 3

2x = -3

x = -3/2

The x-intercept is (-3/2, 0).

Y-Intercept:

Setting x = 0:

y = 2(0) + 3

y = 3

The y-intercept is (0, 3).

Therefore, for the equation y = 2x + 3, the intercepts with the axes are (-3/2, 0) for the x-intercept and (0, 3) for the y-intercept.

The answer of the given question based on the Triangle is the length of AC is approximately 12.81 centimeters (rounded to the nearest tenth of a centimeter).

We have,

The Pythagorean theorem is  mathematical principle that relates to three sides of right triangle. It states that in  right triangle, square of length of hypotenuse (side opposite the right angle) is equal to sum of the squares of the lengths of other two sides.

Since ABCD is a kite, we know that AC and BD are diagonals of the kite, and they intersect at right angles. Let E be the point where AC and BD intersect. Also, since DE = EB, we know that triangle EDB is Equilateral.

We can use Pythagorean theorem to find length of AC. Let's call length of AC "x". Then we have:

(AD)² + (CD)² = (AC)² (by Pythagorean theorem in triangle ACD)

Substituting the given values, we get:

(8)² + (10)² = (x)²

64 + 100 = x²

164 = x²

Taking square root of both sides, we will get:

x ≈ 12.81

Therefore, the length of AC is approximately 12.81 centimeters (rounded to the nearest tenth of a centimeter).

To know more about Right triangle visit:

brainly.com/question/24050780

#SPJ1

Answer:

Average value of f ≈ -1.848

Step-by-step explanation:

The average value of a continuous function f(x) on a closed interval [a, b] is given by:

average value of f = (1/(b-a)) * integral of f(x) dx over [a, b]

So in this case, the average value of f on the interval [2, 6] is:

average value of f = (1/(6-2)) * integral of f(x) dx over [2, 6]

We can simplify the integral by using the product rule for differentiation and integrating by parts:

integral of f(x) dx = integral of (x^2 + x) cos(5x) dx
= (1/5) x^2 sin(5x) + (2/25) x cos(5x) - (2/125) sin(5x) + C

where C is a constant of integration.

So the average value of f on [2, 6] is:

average value of f = (1/4) * [(1/5) (6^2) sin(5*6) + (2/25) (6) cos(5*6) - (2/125) sin(5*6)
- (1/5) (2^2) sin(5*2) - (2/25) (2) cos(5*2) + (2/125) sin(5*2)]
≈ -1.848

To Know more about continuous function refer  here
https://brainly.com/question/30501770#
#SPJ11

The curve is concave downward on the interval (-∞, -1/5).

To determine the intervals where the curve y=∫(from 0 to x) (5t^2 + 2t + 7)dt is concave downward, we'll first find its second derivative. Since y is given as an integral, we can find the first derivative, y', by differentiating the integrand with respect to x:
y'(x) = 5x^2 + 2x + 7
Next, we'll find the second derivative, y''(x), by differentiating y'(x) with respect to x:
y''(x) = 10x + 2
Now, to find where the curve is concave downward, we need to determine where y''(x) is negative. To do this, we'll solve the inequality:
10x + 2 < 0
Subtract 2 from both sides:
10x < -2
Now, divide by 10:
x < -1/5
Therefore, the curve is concave downward on the interval (-∞, -1/5). In interval notation, this is written as:
Answer: (-∞, -1/5)

To know more about Concave Downward visit:
https://brainly.com/question/28978734
#SPJ11

Surfaces like ice and snow have significantly lower drag factors, ranging from 0.10 to 0.25 and 0.10 to 0.55, respectively.

The drag factor, or coefficient of friction, is a crucial factor in determining the minimum speed of a vehicle before applying the brakes based on the length of the skid marks.

For cement surfaces with a drag factor ranging from 0.55 to 1.20, a higher drag factor implies a greater resistance to motion and requires a higher minimum speed to produce a skid mark as wide as a football field (160 ft).

Asphalt surfaces typically have a drag factor ranging from 0.50 to 0.90. Similar to cement, a higher drag factor on asphalt would correspond to a higher minimum speed required for a football field-length skid mark, while a lower drag factor would yield a lower minimum speed.

On gravel surfaces, which have a drag factor of 0.40 to 0.80, a higher drag factor necessitates a higher minimum speed to generate a skid mark of the desired length.

Surfaces like ice and snow have significantly lower drag factors, ranging from 0.10 to 0.25 and 0.10 to 0.55, respectively.

Thus, the drag factor, which depends on the pavement type and road conditions, plays a critical role in determining the minimum speed required to produce a skid mark of a specific length.

For more details regarding coefficient of friction, visit:

https://brainly.com/question/29281540

#SPJ1

If the range on an X-bar-R chart suddenly and significantly increases, it indicates an increase in process variation. In this scenario, the mean (X-bar) may or may not be affected.

The mean represents the central tendency or average value of the process, while the range measures the dispersion or variation within the process.

If the mean remains stable and unaffected despite the increase in range, it suggests that the process average is still within control. However, if the range increase is accompanied by a significant shift in the mean, it indicates a potential shift in the process average.

To make a definitive determination, additional analysis and investigation are necessary to identify the underlying cause of the increased range and its impact on the process mean.

This could involve examining individual data points, performing hypothesis testing, or conducting further statistical analysis to assess the process stability and potential issues.

Learn more about mean here : brainly.com/question/31101410

#SPJ11

The charge required to form 1.00 pound (454 g) of Al(s) from an Al³⁺ salt is 3) 1.62 x 10⁶ C.

To determine the charge required to form 1.00 pound (454 g) of Al(s) from Al³⁺ salt, we need to calculate the number of moles of Al and then convert it to coulombs using Faraday's constant.

Calculate the number of moles of Al:

Given mass of Al = 454 g

Molar mass of Al = 26.98 g/mol

Number of moles of Al = mass of Al / molar mass of Al

Number of moles of Al = 454 g / 26.98 g/mol ≈ 16.84 mol

Convert moles of Al to coulombs:

Given: 1 Faraday = 96,500 C

Charge (coulombs) = Number of moles of Al * Faraday's constant

Charge (coulombs) = 16.84 mol * 96,500 C/mol

Charge (coulombs) ≈ 1.62 x 10⁶ C

Therefore, the charge required to form 1.00 pound (454 g) of Al(s) from an Al³⁺ salt is approximately 1.62 x 10⁶ C (option 3).

To learn more about pound here:

https://brainly.com/question/30760349

#SPJ4

To find the equation of the tangent plane to surface S at point (7,5,4), we first need to find the partial derivatives of the parameterization function r(u,v).
∂r/∂u = <3, 15u^2, 0>
∂r/∂v = <2, 0, 2v>
Evaluating these partial derivatives at (7,5,4), we get
∂r/∂u (7,5) = <3, 1875, 0>
∂r/∂v (7,5) = <2, 0, 8>
Next, we can find the normal vector to the tangent plane by taking the cross product of these partial derivatives:
N = ∂r/∂u x ∂r/∂v = <-15000, 6, -5625>
The equation of the tangent plane can then be written as:
-15000(x-7) + 6(y-5) - 5625(z-4) = 0
To set up the double integral that represents the surface area of S, we can use the formula:
Surface area = ∫∫ ||∂r/∂u x ∂r/∂v|| dA
where dA = ||∂r/∂u x ∂r/∂v|| du dv
Plugging in our parameterization function and taking the cross product of the partial derivatives as before, we get:
||∂r/∂u x ∂r/∂v|| = sqrt(2250000u^2 + 4v^2 + 42187500u^4)
So the surface area of S can be found by integrating this expression over the given ranges of u and v:
∫∫ sqrt(2250000u^2 + 4v^2 + 42187500u^4) du dv, 0 ≤ u ≤ 8, 0 ≤ v ≤ 6.

To know more about partial derivatives visit:

https://brainly.com/question/30365299

#SPJ11

To find the curl of F, we need to compute the determinant of the following matrix:

| i    j    k   |

| ∂/∂x ∂/∂y ∂/∂z |

| 2xy  10y  7z  |

Expanding the determinant, we get:

i(7 - 0) - j(0 - 0) + k(0 - 20x)

= (7 - 20x)k

Therefore, the curl of F is (0, 0, 7 - 20x).

To check if there is a function f such that F = ∇f, we need to compute the partial derivatives of each component of F with respect to the corresponding variable. If these partial derivatives are equal, then there exists a scalar function f such that F = ∇f.

∂F_x/∂y = 2x

∂F_y/∂x = 2x

Since these partial derivatives are not equal, there is no function f such that F = ∇f. Therefore, the answer is "no" (n).

To know more about matrix refer here:

https://brainly.com/question/29132693

#SPJ11

True. Pearson's r is indeed the technical term for the correlation coefficient that is most often used in psychological research. The correlation coefficient measures the strength and direction of the linear relationship between two variables. It quantifies the extent to which changes in one variable are associated with changes in the other variable.

Pearson's correlation coefficient, denoted by the symbol r, is specifically used to assess the linear relationship between two continuous variables. It ranges from -1 to 1, where a value of -1 indicates a perfect negative linear relationship, 1 indicates a perfect positive linear relationship, and 0 indicates no linear relationship.

Psychological research often involves examining the relationships between various psychological constructs, such as intelligence and academic performance, self-esteem and mental health, or stress and job satisfaction. Correlation analysis using Pearson's r allows researchers to determine the strength and direction of these relationships.

By calculating Pearson's correlation coefficient, researchers can assess the degree of association between variables and make informed interpretations about the nature and strength of the relationship. This information is valuable in understanding patterns, making predictions, and informing interventions or treatments in psychological research and practice.

Learn more about Correlation here: brainly.com/question/32386183

#SPJ11

The estimated value of the slope is given by B. b1.

In a simple linear regression model with one predictor variable x, the slope coefficient is denoted as β1 in the population and estimated as b1 from the sample data. The slope represents the change in the response variable y for a unit increase in the predictor variable x. Therefore, b1 is the estimated value of the slope coefficient based on the sample data, and it can be used to make predictions for new values of x.

what is slope?

In mathematics and statistics, the slope is a measure of how steep a line is. It is also known as the gradient or the rate of change.

In the context of linear regression, the slope refers to the coefficient that measures the effect of an independent variable (often denoted as x) on a dependent variable (often denoted as y).

To learn more about slope visit:

brainly.com/question/3605446

#SPJ11

Answer:

115 persons in a population of 4,399 became ill with a disease of unknown etiology. The 115 cases occurred in 77 households.

Step-by-step explanation:

Answer:

  -1 ≤ x ≤ 2

Step-by-step explanation:

You want the solution to |x +1| +|x -2| = 3.

We find it convenient to solve these absolute value equations using a graphing calculator. When we subtract 3 from both sides, we have ...

  |x +1| +|x -2| -3 = 0

The solutions will show on the graph as places where the expression has a value of 0, that is, the x-intercepts.

The left-side expression has a value of 0 for all values of x between -1 and +2, inclusive. That is, the solution is ...

  -1 ≤ x ≤ 2

The absolute value function is piecewise defined:

  |x| = x . . . . for x ≥ 0

  |x| = -x . . . . for x < 0

That is, the behavior of the function changes at x=0.

In the given equation the absolute value function arguments are zero at ...

  x +1 = 0   ⇒   x = -1

  x -2 = 0   ⇒   x = 2

These x-values divide the domain of the equation into three parts.

In this domain, both arguments are negative, so the equation is actually ...

  -(x +1) -(x -2) = 3

  -2x +1 = 3

  -2x = 2

  x = -1 . . . . . . not in the domain

In this domain, the argument (x+1) is positive, but the argument (x-2) is negative. That means the equation is ...

  (x +1) -(x -2) = 3

  1 +2 = 3

True for all x in this domain.

In this domain, both arguments are positive, so the equation is ...

  (x +1) +(x -2) = 3

  2x -1 = 3

  2x = 4

  x = 2 . . . . in the domain (this point was excluded from x < 2).

The solution is -1 ≤ x ≤ 2.

The conditional probability that the sum is greater than 2 given that neither die is a 1 is 5/6.

To find the conditional probability, we need to first calculate the probability of the event "the sum of two fair 6-sided dice is greater than 2" and "neither die is a 1".

The probability of the sum being greater than 2 can be calculated by listing all the possible outcomes and counting the number of outcomes that satisfy the condition.

There are 36 possible outcomes, and the only outcomes that don't satisfy the condition are (1,1), so there are 35 outcomes that satisfy the condition.

Therefore, the probability of the sum being greater than 2 is 35/36.

The probability of neither die being a 1 can be calculated by considering the complementary event, which is the probability of at least one die being a 1.

The probability of one die being a 1 is 1/6, so the probability of at least one die being a 1 is 2/6 = 1/3 (since there are two dice).

Therefore, the probability of neither die being a 1 is 1 - 1/3 = 2/3.

Now, to find the conditional probability, we need to use Bayes' theorem:

P(sum > 2 | neither die is 1) = P(neither die is 1 | sum > 2) * P(sum > 2) / P(neither die is 1)

We have already calculated P(sum > 2) and P(neither die is 1), so we just need to find P(neither die is 1 | sum > 2).

To find P(neither die is 1 | sum > 2), we need to consider the outcomes that satisfy the condition "sum > 2".

There are 35 such outcomes, and of those, 10 have at least one 1 (namely, (1,2), (2,1), (1,3), (3,1), (1,4), (4,1), (1,5), (5,1), (1,6), and (6,1)). Therefore, the probability of neither die being a 1 given that the sum is greater than 2 is:
P(neither die is 1 | sum > 2) = (35 - 10) / 35 = 3/7

Plugging this and the previously calculated probabilities into Bayes' theorem, we get:
P(sum > 2 | neither die is 1) = (3/7) * (35/36) / (2/3) = 5/6

Therefore, the conditional probability that the sum is greater than 2 given that neither die is a 1 is 5/6.

Know more about conditional probability here:

https://brainly.com/question/10739997

#SPJ11

R = C (S/P)^k where C = ±C' is a constant of integration. This is the general solution to the differential equation.

To solve the differential equation dR/R = k S/P, we can separate the variables and integrate both sides with respect to their respective variables:

dR/R = k S/P

ln|R| = k ln|S/P| + C

where C is an arbitrary constant of integration. Exponentiating both sides, we get:

|R| = e^(k ln|S/P| + C)

|R| = e^(ln|S/P|^k) e^C

|R| = C' (S/P)^k

where C' = e^C is another arbitrary constant of integration. Since the absolute value of R is always positive, we can drop the absolute value signs and write:

Know more about integration here:

https://brainly.com/question/18125359

#SPJ11

The travel time T between home and office is expected to be between 20 and 40 minutes depending upon traffic. Based on experience, the average travel time is 30 minutes and the corresponding variance is 20 minutes.What is the expected value of the travel time?The expected value of the travel time is the average of the travel time between the home and office, which is given as 30 minutes.What is the standard deviation of the travel time?The standard deviation of the travel time is the square root of the variance which is given as follows:Variance = 20 minutesStandard deviation = √Variance= √20= 4.47 minutes.What is the probability of travel time being less than 25 minutes?Let X be the random variable for travel time between home and office.X ~ N(30, 20)We need to find P(X < 25).First, we find the z-score as follows:z = (x - μ) / σz = (25 - 30) / 4.47z = -1.12Using a standard normal distribution table, we can find the probability as:P(X < 25) = P(Z < -1.12) = 0.1314Therefore, the probability of travel time being less than 25 minutes is 0.1314.

a) The expected travel time is : 30 minutes.

b) The standard deviation of travel times is: 4.47 minutes

c) The probability that the travel time is less than 25 minutes is 0.1314.  

a) The expected travel time is simply the average travel time between home and office, given as 30 minutes.

b) The standard deviation of travel times is simply the square root of the variance and is expressed as:

Difference = 20 minutes

therefore:

standard deviation = √variance

standard deviation = √20

Standard deviation = 4.47 minutes.

c) Let X be the random variable for travel time between home and office. X to N(30,20)

I need to find P(X < 25).

First, find the Z-score from the following formula:

z = (x - μ)/σ

z = (25 - 30)/4.47

z = -1.12

The probabilities from the online p-values ​​in the Z-score calculator are:

P(X < 25) = P(Z < -1.12) = 0.1314

Therefore, the probability that the travel time is less than 25 minutes is 0.1314.  

Read more about expected Value at: https://brainly.com/question/24305645

#SPJ4

Complete question is:

The travel time T between home and office is expected to be between 20 and 40 minutes depending upon traffic. Based on experience, the average travel time is 30 minutes and the corresponding variance is 20 minutes.

What is the expected value of the travel time?

What is the standard deviation of the travel time?

What is the probability of travel time being less than 25 minutes?

Checking by differentiation,

y′ = -6sin(3t) + 12cos(3t)

y′′ = -18cos(3t) - 36sin(3t)

9y = y′ = -6sin(3t) + 12cos(3t)

y ′′ + 9y = 0

To verify that y=2cos3t+4sin3t is a solution to y ′′ +9y=0, we need to differentiate y twice and substitute the result into the differential equation.

First, we find the first derivative of y with respect to t:

y′ = -6sin(3t) + 12cos(3t)

Then, we take the second derivative of y with respect to t:

y′′ = -18cos(3t) - 36sin(3t)

Next, we substitute y′′ and y into the differential equation:

y′′ + 9y = (-18cos(3t) - 36sin(3t)) + 9(2cos(3t) + 4sin(3t))

Simplifying this expression, we get:

y′′ + 9y = -18cos(3t) - 36sin(3t) + 18cos(3t) + 36sin(3t)

y′′ + 9y = 0

Therefore, we have shown that y=2cos3t+4sin3t is a solution to y ′′ +9y=0, as the sum of the two terms reduces to 0 when substituted into the differential equation. This verifies that the function y satisfies the differential equation.

To know more about differentiation refer here :

https://brainly.com/question/31583235#

#SPJ11

After 19 hours, approximately 53.36 milligrams of the radioactive substance will remain.

To find out how many milligrams of the radioactive substance will remain after 19 hours, we need to use the exponential decay formula:  [tex]N(t) = N(0) (e)^{-λt}[/tex]
Where:
N(t) = amount of substance remaining at time t
N0 = initial amount of substance (160 mg)
e = base of natural logarithm (approximately 2.718)
λ = decay constant
t = time in hours

-First, we need to find the decay constant (λ). We know that after 12 hours, 80 mg of the substance remains:
[tex]80 = 160 e^{(-λ (12))}[/tex]
-Divide by 160: [tex]0.5 = e^{(-λ (12))}[/tex]
-Take the natural logarithm of both sides: [tex]ln(0.5) = 12 (-λ)[/tex]
-Now, find λ:  λ = [tex]λ = \frac{-ln(0.5)}{12}= 0.0578[/tex]

Next, we need to find the amount of substance remaining after 19 hours:
[tex]N(19) = 160 e^{(-0.0578)(19))}[/tex]
[tex]N(19) = 160 e^{(-1.0928)} = 160(0.3335)[/tex]
N(19) = 53.36 mg

So, after 19 hours, approximately 53.36 milligrams of the radioactive substance will remain.

To know more about "Exponential decay" refer here:

https://brainly.com/question/11750120#

#SPJ11

We integrate the given function with respect to y first, and then with respect to x. The value of the given double integral is (1/4) * (2/3) * (2√2)^3 = (16√2)/3.

We integrate the given function with respect to y first, and then with respect to x. The limits of integration for y are from 0 to √(2-x^2), and the limits of integration for x are from 0 to √2. Thus, we have:

=∫ √2 0 ∫ √2−x^2 0 (x^2 y^2) dydx

= ∫ √2 0 (x^2) ∫ √2−x^2 0 (y^2) dydx (using Fubini's theorem)

= ∫ √2 0 (x^2) [(y^3)/3] ∣∣ 0 √2−x^2 dx

= (1/3) ∫ √2 0 (x^2) [(2−x^2)^3/2] dx

[Let u = 2−x^2, then du/dx = −2x, and so dx = −(1/2x) du.]

= −(1/6) ∫ 2 0 u^(3/2) du

= (1/6) [(2/5) u^(5/2)] ∣∣ 2 0

= (1/6) * (2/5) * (2√2)^3

= (16√2)/3.

Therefore, the value of the given double integral is (16√2)/3.

Learn more about double integral here:

https://brainly.com/question/27360126

#SPJ11