The homogeneous equation
y'' + y = 0
has characteristic equation
r² + 1 = 0
with roots at r = ± √(-1) = ± i, and so the characteristic solution is
y = C₁ cos(x) + C₂ sin(x)
Using the method of undetermined coefficients, suppose
y = a x cos(x) + b x sin(x)
(we would normally consider y = a cos(x) + b sin(x), but cos(x) and sin(x) are already part of the characteristic solution)
The derivatives are
y' = a cos(x) - a x sin(x) + b sin(x) + b x cos(x)
y' = (b - a x) sin(x) + (a + b x) cos(x)
and
y'' = -a sin(x) + (b - a x) cos(x) + b cos(x) - (a + b x) sin(x)
y'' = (-2a - b x) sin(x) + (2b - a x) cos(x)
Then
y'' + y = (-2a - b x) sin(x) + (2b - a x) cos(x) + a x cos(x) + b x sin(x)
7 sin(x) = -2a sin(x) + 2b cos(x)
and it follows that a = -7/2 and b = 0.
So, the general solution to the DE is
y = C₁ cos(x) + C₂ sin(x) - 7/2 x cos(x)
which means the only valid solutions from the given choices are
y = 7 sin(x)
y = 7 cos(x)
Please help meee! I will give brainlist to quickest answer !!!
What is the equation of this graphed line?
Answer:
You said quick so here it is
[tex]y-6=2(x-2)[/tex]
You work for a consumer advocacy agency and want to estimate the populations means cost of monthly maintenance on a car. It is assumed that the average monthly cost of maintenance is $210 dollars. In a random sample of 100 cars, you find the average monthly maintenance cost was $185. Assume that the population standard deviation is known to be $125; Use a 0.03 significance level to test the claim that the population mean weight of cost of maintenance differs from 210 lbs. State the null and alternate hypothesis test
A) H0: μ≤185
Ha: μ>185
B) H0: μ≥210
Ha: μ<210
C) H0=210
Ha: μ=185
D) H0: μ=210
Ha: μ ≠ 210
According to the desired test, the hypothesis are given by:
D) H0: μ=210
Ha: μ ≠ 210
At the null hypothesis, it is tested if the population mean is of 210 lbs, that is:
[tex]H_0: \mu = 210[/tex]
At the alternative hypothesis, it is tested if the population mean differs from 210 lbs, that is:
[tex]H_a: \mu \neq 210[/tex]
Hence, the correct option is:
D) H0: μ=210
Ha: μ ≠ 210
A similar problem is given at https://brainly.com/question/25707631
Which variable expression represent the word phrase? The sum of 10 and the product of 7 and a number
Answer:
Step-by-step explanation:
y = 7x + 10
slope-intercept form of a linear equation
Is there a formula for
[tex] {a}^{m} + {a}^{n} [/tex]
?
Answer:
No
Step-by-step explanation:
There is no formula
There is no formula
HELp PLeaSE ‼️‼️URGENT
Find the equation of the line of best fit for the points (-4, 10).(-1, 5), (2, -1) (3, (5, --- 7). O
A. y = -2x + 2
B. y = 2x - 2
C. y = 2x - 0.98
D. y = -2x - 0.98
THANKS ^_^ ! ! !
8 grade math part 2 help me
Answer:
287
Step-by-step explanation:
Reflex angle:
an angle greater than 180° and less than 360°
360-73=287
Find the slope of the line.
Ay
6
-2, 4)
(
4
2
(2, 2)
-4
-2
2
4
Х
-2
4
The slope is
Answer:
-1/2 is the slope of the graph.
Tomatoes that regularly sell for $0.55 per pound are on sale for 20% off the regular price. What is the sale price?
How much larger is 8 x 10^8 compared to 2 x 10^5?
О 4 times larger
O 40 times larger
O 400 times larger
O 4,000 times larger
A salesperson earns a commission of $308 for selling $ 2200 in merchandise. Find the commission rate.
Answer:$247
Step-by-step explanation
A bank loaned out $30,500, part of it at the rate of 5% annual interest, and the rest at 4% annual interest. The total interest earned for both loans was $1,405.00. How much was loaned at each rate?
$What was loaned at 5% and
$ What was loaned at 4%.
Step-by-step explanation:
Ok, so we know the bank loaned part of the $17,500 at a 4% interest rate. Lets call this loan amount x. Then the rest of the 17,500 was loaned at a 9% interest rate. Whatever this amount was, we can define it as 17,500 - x. We also know that the total interest earned was $1,100. With this information, we can form the following equation:
.04(x) + .09(17500 - x) = 1100
Multiply the .09 times the inside of the parentheses:
.04x + 1575 - .09x = 1100
Simplify:
-.05x + 1575 = 1100
-.05x = -475
x = 9500
Since x is originally the amount loaned at the 4% interest rate, we know that $9,500 was loaned at a 4% interest rate.
To figure out the other amount loaned at 9%, simply subtract 9,500 from 17,500 -- this gets us 8,000. So $8,000 was loaned at a 9% interest rate.
I hope this helps!
Floretta, a pitcher, claims that her pitch speed is less than 46 miles per hour, on average. Several of her teammates do not believe her, so she decides to do a hypothesis test, at a 5% significance level, to persuade them. She throws 24 pitches. The mean speed of the sample pitches is 37 miles per hour. Floretta knows from experience that the standard deviation for her pitch speed is 5 miles per hour.
H0: μ≥46; Ha: μ<46
α=0.05 (significance level)
What is the test statistic (z-score) of this one-mean hypothesis test, rounded to two decimal places?
If the exchange rate is 1.5 U.S. dollars / 1 euro, how many U.S. dollars would be equivalent to 20 euros?
A. $1.50
B. $18.50
C. $30.00
D. $13.30
The answer is C because 1 times 20 is 20 and .5 times 20 is 10 then you get 30
Answer: C.) $30.00
Step-by-step explanation: If 1.5 U.S. dollars equals 1 euro, then 1*20 would be 20 euros. So then, you could multiply 0.5*20 to get 10. Finally, you add $10 + $20 to get $30 U.S. dollars.
0.5*20= $10
20+10= $30
A car travels 108 miles on 8 gallons of gas. Find the distance the car can travel on 25 gallons of gas.
337.5 miles, or 337 miles!
Answer: It will be able to travel 162 miles
Step-by-step explanation:
What is the mass of an object that has 50 newtons of force and is accelerating at the rate of 2 m/s/s
HELP PLEASE!! Do not explain need full answer
Answer:
F= ma
m = F/a
m = 50/2
m = 25
Answer equal 25
Lisa has $200 in her savings account. This is 40% of the money she needs to take a weekend trip. What is the total cost of the trip she wants to take?
The total cost of the trip Lisa wants to take over the weekend is $500.
Let the total cost of the trip be T.Given the following data:
Savings account balance = $200Percent of trip expenses = 40%To determine the total cost of the trip Lisa wants to take over the weekend:
Since the percentage of the money in Lisa's savings account is equal to forty percent (40%) of what is required for the total cost of the trip. Thus, we would multiply the total cost of her trip by 40% and equate it to $200.
Total cost of her trip:
[tex]\frac{40}{100} \times T = 200\\\\0.4T=200\\\\T=\frac{200}{0.4}[/tex]
Total cost, T = $500.
Read more: https://brainly.com/question/2021001
Solve.
Write an expression for the total cost (in dollars) of Sam's purchase if he buys x candies costing 39 cents each and y bars of chocolate cost $1.25 each.
a. (0.39 + x) ∙ (1.25 + y)
b. 0.39x + 1.25y
c. 1.64(x + y)
d. 39x + 1.25y
Answer:
the answer to the question is c
Lola is in the process of forecasting the sales growth rate for an early-stage venture specilizing in the production of durable running shoes. Lola predicts a 0.15 probability of an 85% growth in sales, a 0.2 probability of a 20% growth in sales, a 0.45 probability of a 10% growth in sales, nd a 0.20 probability of a 20% decrease in sales. What is the expected sales growth rate of the venture?
Answer:
Step-by-step explanation:
Expected growth = 0.15*85 + 0.20 *20 + 0.45*10+0.20 * -20
= 17.25%.
Suraj took a slice of pizza from the freezer and put it in the oven. The pizza’s temperature (in degrees celsius) as a function of time (in minutes) is graphed. What was the pizza’s temperature after 2 minutes?
For this case, the first thing we should do is write the linear function that best suits the table.
In this case we have the following function:
y = 7.5x - 5
C = 7.5t-5
For C = 100 we have:
100 = 7.5t-5
We clear the time:
t = (100 + 5) / (7.5)
t = 14
Answer:
it did take the pizza to reach 100 degrees Celsius about 14 minutes
[6x(5-3)+9]-5 with step by step
Answer: 10
Step-by-step explanation: [30-24+9]=15-5=10
The answer after calculation the given expression using PEDMAS rule: [6x(5-3)+9]-5 is 16.
What is the answer using PEDMAS?The given expression, [6x(5-3)+9]-5, can be simplified using the order of operations, also known as PEDMAS P – Parenthesis First: B – Brackets First
E – Exponents
D – Division
M – Multiplication
A – Addition
S – Subtraction
First, we evaluate the expression inside the bracket: 5-3, which equals 2. Substituting this result back into the expression, we have [6x2+9]-5.
For the next step, we perform the multiplication operation. Multiplying 6 by 2 gives us 12. Now our expression becomes [12+9]-5.
Moving on to addition, we add 12 and 9, resulting in 21. Our expression now becomes [21]-5.
Finally, we subtract 5 from 21, which gives us 16. Thus, the value of the expression [6x(5-3)+9]-5 is 16.
Read more about PEDMAS here: https://brainly.com/question/345677
#SPJ6
What’s is log17 divided by 4
Answer:
log(17 1/4)
Step-by-step explanation:
8. Lara invested a total of $1000 in two simple interest accounts. Account A pays
5% annual interest while Account B, pays 6% annual interest. The total interest
she earned after one year was $58. How much did she invest in each account?
Answer:
$200 at 5%$800 at 6%Step-by-step explanation:
Let x represent the amount invested at the higher rate. Then 1000-x is the amount invested at the lower rate. The total earnings are ...
0.05(1000-x) +0.06x = 58
50 +0.01x = 58 . . . . . . . . . . . simplify
0.01x = 8 . . . . . . . . . . . . . . . subtract 50
x = 800 . . . . . . . . . . . . . . . multiply by 100; amount at 6%
(1000-x) = 200 . . . . . . . find the amount invested at 5%
Lara invested $200 at 5% and $800 at 6%.
Evaluate the expression.
3x + 2y for x = 4.2, y = 2.7
Answer:
18
Step-by-step explanation:
4.2 • 3= 12.60
2.7 • 2= 5.4
12.6+ 5.4=
18.0
Is the inequality 5-x^2<4 true for x=1?
5 - x² < 4
- x² < 4 - 5
- x² < - 1
=》x² < 1
Now, let's check with x = 1
x² < 1
(1)² < 1
1 < 1
1 is not less than or greater than 1. They are equals. So, the inequality 5 - x² < 4 is NOT true for x = 1.
_____
Hope it helps ⚜
Cost 500 charge 25 per unit
Answer:
20 units
Step-by-step explanation:
Because it is 25 per unit, and 500, you can do 500/25=20
4.
(03.02)
Match each statement (term) with its value in relation to 0 (definition). (10 points)
1.
Oliver owes his sister $27.
2.
A building is 38 feet tall.
3.
Erica jumped 2.7 feet above ground.
4.
The scuba diver was 38 feet below sea level.
5.
The basement is 8.3 feet below ground.
a.
38
b.
-38
c.
-8.3
d.
-27
e.
2.7
The statements with their relation to 0 are:
Oliver owes his sister $27. [tex]\to[/tex] -27 A building is 38 feet tall. [tex]\to[/tex] 27 Erica jumped 2.7 feet above ground. [tex]\to[/tex] 2.7 The scuba diver was 38 feet below sea level. [tex]\to[/tex] -38 The basement is 8.3 feet below ground. [tex]\to[/tex] -8.3Statements that represent positions above the sea level are illustrated using the positive sign, while positions below the sea level are represented using the negative sign.
The above highlights imply that the following statements would be represented with positive sign:
A building is 38 feet tall.Erica jumped 2.7 feet above ground.This is so, because height and positions above the ground are above the sea level
Also, the following statements would be represented with negative sign:
Oliver owes his sister $27. [tex]\to[/tex] -27 The scuba diver was 38 feet below sea level. [tex]\to[/tex] -38 The basement is 8.3 feet below ground. [tex]\to[/tex] -8.3This is so, because debt and positions below the ground are below the sea level
Read more about positions at:
https://brainly.com/question/4692136
half of the sum of six and three then divided by 7
Answer:
45/70
Step-by-step explanation:
easy though thats it
What is the gradient of the graph shown?
Give your answer in its simplest form.
Answer:
[tex]\displaystyle m = \frac{-1}{3}[/tex]
General Formulas and Concepts:
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightAlgebra I
Coordinate Planes
Coordinates (x, y)Slope Formula: [tex]\displaystyle m = \frac{y_2 - y_1}{x_2 - x_1}[/tex]
Step-by-step explanation:
Step 1: Define
Identify points from given graph.
Point (0, -1)
Point (-3, 0)
Step 2: Find slope m
Simply plug in the 2 coordinates into the slope formula to find slope m.
Substitute in points [Slope Formula]: [tex]\displaystyle m = \frac{0 - -1}{-3 - 0}[/tex][Order of Operations] Evaluate: [tex]\displaystyle m = \frac{1}{-3}[/tex]What is the correct unit rate?And what is Jessie's likely error?
Answer:
4
Step-by-step explanation:
1[tex]\frac{1}{2} / \frac{1}{8} = \frac{1}{2} * \frac{8}{1} = \frac{8}{2} = 4[/tex]
she forget that fraction will reverse if it move below or up side, I think
10+8x > 2 Solve each inequality
Answer:
x>-1
Step-by-step explanation:
8x>2-10
8x>-8
x>-1
Answer:
x>-1
interval notation: (-1,infinty)