Answer:
answer is d if its wrong i am sorry
giải phương trình y′′ − 7y′ + 6y = sin x.
Start with the underlying homogeneous equation:
[tex]y''-7y'+6y=0[/tex]
which has characteristic equation
[tex]r^2-7r+6=(r-6)(r-1)=0[/tex]
with roots at r = 6 and r = 1. So the characteristic solution is
[tex]y_c=C_1e^{6x}+C_2e^x[/tex]
Now for the particular solution, we can use the method of undetermined coefficients, with the following ansatz (the "guess" solution) and its derivatives,
[tex]y_p=a\cos x+b\sin x[/tex]
[tex]{y_p}'=-a\sin x+b\cos x[/tex]
[tex]{y_p}''=-a\cos x-b\sin x[/tex]
Substituting these into the original equation gives
[tex](-a\cos x-b\sin x)-7(-a\sin x+b\cos x)+6(a\cos x+b\sin x)=\sin x[/tex]
[tex](5a-7b)\cos x+(7a+5b)\sin x=\sin x[/tex]
[tex]\implies\begin{cases}5a-7b=0\\7a+5b=1\end{cases}\implies a=\dfrac7{74},b=\dfrac5{74}[/tex]
So the particular solution is
[tex]y_p=\dfrac7{74}\cos x+\dfrac5{74}\sin x[/tex]
and hence the general solution is
[tex]y=y_c+y+p=\boxed{C_1e^{6x}+C_2e^x+\dfrac7{74}\cos x+\dfrac5{74}\sin x}[/tex]
Steven earns extra money babysitting. He charges $40.50 for 6 hours and $54.00 for 8 hours. Enter an equation to represent the relationship. Let x represent the number of hours Steven babysits and y represent the amount he charges.
Answer:
6.75 * x =y
Step-by-step explanation:
In this question, for is a keyword here we can use to represent division. If he charges $40.50 for 6 hours, this means we can represent this as [tex]\frac{40.50dollars}{6 hours}[/tex] to calculate the amount babysitting costs for an hour. Our answer is then [tex]\frac{6.75 dollars}{1 hour}[/tex]. A similar division of $54.00 for 8 hours results in a calculation of [tex]\frac{54.00 dollars}{8 hours} = \frac{6.75 dollars}{1hour}[/tex]. This means that for each hour, he charges 6.75 dollars, the same amount of money each hour.
Given this information, we can say that an equation to represent this relationship would be that, to calculate the total money Steven earns, we can multiply 6.75 dollars by the amount of hours he works, as he earns 6.75 dollars for each hour, making our equation 6.75 * x =y, with y representing the total amount he charges. If your teacher would
what is the mode for the data set
x
x x x
x x x x x x
_______ __
5 6 7 8 9 10 options 7.8
5
8
9
Answer:
5
Step-by-step explanation:
The mode of a data set is the number that appears most
Find the x- and y intercepts in the table write your answers as separate coordinates
Answer:
1: x intercept:2 y intercept:5
2: x intercept:-7 y intercept:1
3: x intercept:2 y intercept:-2
4: x intercept: 1 y intercept: -2
Step-by-step explanation:
The y intercept is whenever the x unit is at 0, and the x intercept is whenever the y intercept is at 0.
(-5/2;5) (1/7;1) (1;-2) (2;-2)
A market has two check out lines. Let X be the number of customers at the express checkout line at a particular time of day. Let Y denote the number of customers in the super-express line at the same time. The joint probability mass function of (X, Y) is given below. What is the probability of having only one customer at the express checkout line when there are more than two customers in the super-express line at the same time
parabola
Given that tanθ= [tex]-\frac{9}{4}[/tex] and [tex]\frac{\pi }{2\\}[/tex]<θ<π , find the exact values of the trigonometric functions.
9514 1404 393
Answer:
sin(θ) = (9√97)/97cos(θ) = (-4√97)/97csc(θ) = (√97)/9sec(θ) = (-√97)/4cot(θ) = -4/9Step-by-step explanation:
The angle is in the 2nd quadrant, where the sine is positive and the cosine is negative.
tan^2(θ) +1 = sec^2(θ) = (-9/4)^2 +1 = 97/16 ⇒ sec = -(1/4)√97
cot(θ) = 1/tan(θ) = -4/9
csc^2(θ) = cot^2(θ) +1 = (-4/9)^2 +1 = 97/81 ⇒ csc = (1/9)√97
sin(θ) = 1/csc(θ) = (9√97)/97
cos(θ) = 1/sec(θ) = (-4√97)/97
This holiday season, Ms. Bastarache organized to give each 9th grader a $10 Dunkin Donuts gift card. Because she bought a lot of cards, Ms. Bastarache tipped the Dunkin Donuts employee $20.
This function represents the relationship between the number of gift cards, c, and T(c), the total cost of the cards.
T(c) = 10c + 20
Be sure to answer BOTH questions below.
1. Determine the total cost, in dollars, for Ms. Bastarache to give out 93 gift cards.
2. Last year, Ms. Bastarache spent $820, how many cards did she purchase?
need help asap plzzzzzz
Answer:
1. $950
2. 80
Step-by-step explanation:
How many sticks would be in pattern number n
Answer:
hey. pls post a pic of the pattern or type in the number of sticks in each term so we could help tou determine the nth term
 Marsha has a bag that contains 4 green marbles, 8 yellow marbles , and 20 red marbles . If she chooses one marble from the bag, what is the probability that the marble is not red?
PLEASE HELP IF YOURE GOOD AT GEOMETRY!!
Answer:
C. 3/8
HOPE THIS HELPS :)
Answer:
c. 3/8
Step-by-step explanation:
first you need the denomerator by adding all marbles together which equals 32. now for the munerator you need the sum of the green and yellow marbles. this equals 12. so your fraction is 12/32. next we simplify. we can divide both numbers by 4. getting us a fraction of 3/8.
Which pairs in the form x,y are solutions to the equation 7x-5y=28?
Answer:
x=4 y=0
Step-by-step explanation:
7(4)-5(0)=28
28-0=28
28=28
Simplify:......................................................
Answer:
...
Step-by-step explanation:...
To test for the significance of a regression model involving 14 independent variables and 255 observations, the numerator and denominator degrees of freedom (respectively) for the critical value of F are:_________
a. 14 and 255.
b. 255 and 14.
c. 13 and 240.
d. 14 and 240.
Answer:
d). 14 and 240
Step-by-step explanation:
According to the Question,
Given that, The regression model involving 14 independent variables and 255 observationsWe need to find out the numerator and denominator freedom degrees ,
k = 14 regression variable
= n - k - 1
= 255 - 14 - 1
= 240 residuals
df=14,240
Now The degree of freedom for F-critical isF_{k,n-k-1}=F_{14,240}
So, The df of the numerator is 14 and df of the denominator is 240
The rate of inflation measures the percentage increase in the price of consumer goods. The rate of inflation in the year 2014 was 2% per year. To get a sense of what this rate would mean in the long run, let's suppose that it persists through 2034.
What would be the cost in 2034 of an item that costs $100 in 2014? (Round your answer to the nearest cent.)
$
Answer:
148.59
Step-by-step explanation:
Inflation is kind of similar to interest and with that bieng said we can (kind of ) use the same formula
the time between 2034 and 2014 is 2034-2014= 20
100(1.02)²⁰=148.5947396
which we can round to 148.59
148.5 is the cost in 2034 of an item that costs $100 in 2014
What is Simple Interest?Simple interest is a quick and easy method of calculating the interest charge on a loan
[tex]A=P(1+r)^{t}[/tex]
where A is the Actual amount
P is Initial amount
t is time period
r is rate of interest
Given,
The rate of inflation measures the percentage increase in the price of consumer goods
The rate of inflation in the year 2014 was 2% per year.
2% is converted to decimal by dividing with 100
2/100=0.02
The time gap between 2014 and 2034 is
2034-2014=20 years
The initial amount is 100
A=100(1+0.02)²⁰
A=100(1.02)²⁰
A=100×1.485
A=148.5
Hence 148.5 is the cost in 2034 of an item that costs $100 in 2014.
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Can I get an awnser to both of these questions? Thank you!
Answer:
y+1=7(x+4) for first one
y-4=5(x-0) for second one
Step-by-step explanation:
point slope form for both of those questions.
the formula for point slope form is
y-y1(y coordinate) = slope(x+x2(x coordinate))
y+1=7(x+4)
Second question:
-1,-1 to 0,4
change in x +1, change in y +5.
5/1 = 5
slope is 5
y-4=5(x-0)
Help with this please
Answer:
I would say 4 to 6 since everything else is decreasing
Step-by-step explanation:
John made this model to show 4/7 * 13/9
Using John's model, what is 4/7 * 13/9? (has to be in fractions)
Answer:
52/63
Step-by-step explanation:
Given the expression
4/7 * 13/9
Taking the product
= (4*13)/(7*9)
= 52/63
Hence the product of both fractions is 52/63
#1
You and your family need to take a taxi to get around town on
your vacation. The taxi service charges $7.50 for the initial
pickup of you and your family and $0.25 per mile. Write an
equation to represent this situation. Then, calculate how much
it would cost if you took the taxi for a 12 mile trip.
Equations
Solutions
y = 0.25x + 7.75
А A
$10.50
3
y = 7.50x + 0.25
B
$18.00
y = 0.25x + 7.50
$90.25
5
Answer:
Equation: y = 0.25x + 7.50
Cost: $10.50
Step-by-step explanation:
Let x be the number of miles and y be the total cost in $.
y = 0.25x + 7.50
If we want to find the total cost of a 12 mi trip, we plug in x=12.
y = 0.25 * 12 + 7.50
y = 3 + 7.50
y=10.50
2 divided by 0.75 please help
Answer:
8/3
Step-by-step explanation:
2/ (3/4) = 2*4/3 =8/3
How much would you pay for: 240 textbooks at $15.40 each, 100 pens at $1.25 each and 30
dozen erasers at 95c each?
Answer:
384950c or $3849.50
Step-by-step explanation:
240x1540=369600
100x125=12500
30x95=2850
369600+12500+2850=384950
What is the missing number in the table?
Answer:
1296
Step-by-step explanation:
the y is multiplying by six each time 6*6 = 36
36*6 = 216
216*6 = 1296
2196 = 7776
graph the function.
for the function whose graph is shown below, which is the correct formula for the function?
A. y = -x + 1
B. y = x - 1
C. y = -x - 1
D. y = x + 1
Answer:
y =x+1
Step-by-step explanation:
The y intercept is 1
The slope is positive
We go up 1 and to the right 1
y = mx+b where m is the slope and b is the y intercept
y = 1x+1
y =x+1
If 137 is subtracted from three times of square of a natural number the result is 55. Find the number
Answer:
8
Step-by-step explanation:
Let the unknown number be x.
Therefore, we can write the question as a mathematical statement and this will be:
3x^2 - 137 = 55. (Note: ^2 = to the power of 2 or "squared"
(In the question, we can break it up as being three times of a square of a natural number = (3x^2) and 137 is subtracted from = (- 137) and the result is 55 = (= 55). Therefore, this gives 3x^2 - 137 = 55
Then, we add 137 first to get rid of the (-137)
Therefore:
3x^2 = 192
Then, we divide 3 from both sides to get rid of the (3) in (3x^2).
Therefore,
x^2 = 64.
So, we square root 64. This gives
x = 8.
Therefore, the answer is 8.
Marcus likes to go for a run each morning before school. He recorded the number of minutes he spends running and the distance he covers. The scatter plot represents the data he collected
Answer:
D. 0.85
Step-by-step explanation:
The data points in the scatter plot are closer to each other along the line of best fit, this means that there is a strong positive association between minutes and distance and therefore, the correlation coefficient would be relatively closer to 1.
The correlation is positive since both variables tend to increase together in the same direction.
Therefore, the best estimate of the correlation coefficient out of the given options would be 0.85
A restaurant charges large parties an amount that depends on the number of people
that are eating. The restaurant charges $650 for 25 people and $1,850 for 80 people.
What is the restaurant charging per person (unit rate)?
Answer:
$26 per person or $23.125 per person for the bigger group
Step-by-step explanation:
I need help with this math problem
Answer: A) (x + 12) and (x + 9)
Step-by-step explanation:
You need to get x^2 + 21x + 108.
A) (x + 12) (x + 9) = x^2 + 12x + 9x + 108 = x^2 + 21x + 108
B) (x - 12) (x - 9) = x^2 - 9x - 12x + 108 = x^2 -21x + 108
C) (x - 27) (x - 4) = x^2 - 4x - 27x + 108 = x^2 - 31x + 108
D) (x + 27) (x + 4) = x^2 + 27x + 4x + 31 = x^2 + 31x + 31
So, the answer is A).
A landscaper buys 1 gallon of plant fertilizer. He uses 1/5 of the fertilizer, and then divides the rest into 3 smaller bottles. How much does he put in each bottle?
Answer:
4/15 gallon per bottle
Step-by-step explanation:
First, we find the remaining fraction of fertilizer after using 1/5. Using our fraction calculator, we see:
1 - 1/5 = 4/5
To find the amount of fertilizer per bottle, we then divide 4/5 by 3 and we get:
4/15 gallon per bottle
The resale value V, in thousands of dollars, of a boat is a function of the number of years t since the start of 2011, and the formula is
V = 12.5 − 1.3t.
(a) Calculate V(3).
(b) In what year will the resale value be 7.3 thousand dollars?
(c) Solve for t in the formula above to obtain a formula expressing t as a function of V.
(d) In what year will the resale value be 3.4 thousand dollars?
Answer:
a) V(3) = 8.6.
b) The resale value will be 7.3 thousand dollars at the start of 2015.
c) [tex]t(V) = \frac{12.5 - V}{1.3}[/tex]
d) 2017
Step-by-step explanation:
We are given the following function:
[tex]V(t) = 12.5 - 1.3t[/tex]
(a) Calculate V(3).
This is V when t = 3. So
[tex]V(3) = 12.5 - 1.3(3) = 8.6[/tex]
So
V(3) = 8.6.
(b) In what year will the resale value be 7.3 thousand dollars?
t years after the start of 2011, and t is found when [tex]V(t) = 7.3[/tex]. So
[tex]V(t) = 12.5 - 1.3t[/tex]
[tex]7.3 = 12.5 - 1.3t[/tex]
[tex]1.3t = 5.2[/tex]
[tex]t = \frac{5.2}{1.3}[/tex]
[tex]t = 4[/tex]
2011 + 4 = 2015
The resale value will be 7.3 thousand dollars at the start of 2015.
(c) Solve for t in the formula above to obtain a formula expressing t as a function of V.
[tex]V(t) = 12.5 - 1.3t[/tex]
[tex]1.3t(V) = 12.5 - V[/tex]
[tex]t(V) = \frac{12.5 - V}{1.3}[/tex]
(d) In what year will the resale value be 3.4 thousand dollars?
t years after 2011, and t is found t when [tex]V = 3.4[/tex]. So
[tex]V(t) = 12.5 - 1.3t[/tex]
[tex]3.9 = 12.5 - 1.3t[/tex]
[tex]1.3t = 8.6[/tex]
[tex]t = \frac{8.6}{1.3}[/tex]
[tex]t = 6.62[/tex]
2011 + 6.62 = 2017
So the year is 2017.
There are 4 teams. Each team plays each other team once. How many games are played?
A 3
B 4
C. 6
D. 12
E 16
Answer:
E) 16
Step-by-step explanation:
4 * 4 = 16
Hope this helps
The solution is Option C.
The number of games played by 4 teams if they play each other only once is given by combinations and is 6 games
What are Combinations?
The number of ways of selecting r objects from n unlike objects is:
ⁿCₓ = n! / ( ( n - x )! x! )
where
n = total number of objects
x = number of choosing objects from the set
Given data ,
Let the total number of teams be n = 4 teams
Each team plays the other team only once , so x = 2
The number of games played by 4 teams if they play each other only once is given by Combination
ⁿCₓ = n! / ( ( n - x )! x! )
Substituting the values in the equation , we get
⁴C₂ = ( 4! ) / 2! x 2!
On simplifying the equation , we get
⁴C₂ = ( 4 x 3 ) / 2 x 1
⁴C₂ = 2 x 3
⁴C₂ = 6 games
Therefore , the value of ⁴C₂ =6
Hence , the number of games is 6 games
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Evaluate ∬_D▒〖42y^2-12x dA〗 where D={(x,y) 0≤x≤4 ,(x-2)2 ≤y≤6
Resuelve el siguiente problema aplicado al sistema de ecuaciones, utilizando cualquiera de los tres métodos aprendidos: Sergio tiene $ 1.950 en monedas de $ 100 y de $ 50. En total tiene 24 monedas. Determina cuántas monedas son de $ 100 y cuántas de $ 50.
Answer:
Tiene 9 monedas de $50 y 15 monedas de $100.
Step-by-step explanation:
Sergio tiene $1950 en monedas de $100 y $50, entonces la primera ecuación es la siguiente:
[tex] 100x + 50y = 1950 [/tex] (1)
Ahora, en total tiene 24 monedas:
[tex] x + y = 24 [/tex] (2)
De la ecuación (2) tenemos:
[tex] x = 24 - y [/tex] (3)
Ahora introduciendo la ecuación (3) en la ecuación (1) y resolviendo para "y" nos queda:
[tex] 100(24 - y) + 50 y = 1950 [/tex]
[tex] 2400 - 100y + 50y = 1950 [/tex]
[tex] y = \frac{450}{50} = 9 [/tex]
Con la ecuación (3) podemos hallar el valor de "x":
[tex] x = 24 - 9 = 15 [/tex]
Por lo tanto, tiene 9 monedas de $50 y 15 monedas de $100.
Espero que te sea de utilidad!