Recall the angle sum identity for cosine:
cos(x + y) = cos(x) cos(y) - sin(x) sin(y)
cos(x - y) = cos(x) cos(y) + sin(x) sin(y)
==> sin(x) sin(y) = 1/2 (cos(x - y) - cos(x + y))
Then rewrite the equation as
sin(4x) sin(5x) + sin(4x) sin(3x) - sin(2x) sin(x) = 0
1/2 (cos(-x) - cos(9x)) + 1/2 (cos(x) - cos(7x)) - 1/2 (cos(x) - cos(3x)) = 0
1/2 (cos(9x) - cos(x)) + 1/2 (cos(7x) - cos(3x)) = 0
sin(5x) sin(-4x) + sin(5x) sin(-2x) = 0
-sin(5x) (sin(4x) + sin(2x)) = 0
sin(5x) (sin(4x) + sin(2x)) = 0
Recall the double angle identity for sine:
sin(2x) = 2 sin(x) cos(x)
Rewrite the equation again as
sin(5x) (2 sin(2x) cos(2x) + sin(2x)) = 0
sin(5x) sin(2x) (2 cos(2x) + 1) = 0
sin(5x) = 0 or sin(2x) = 0 or 2 cos(2x) + 1 = 0
sin(5x) = 0 or sin(2x) = 0 or cos(2x) = -1/2
sin(5x) = 0 ==> 5x = arcsin(0) + 2nπ or 5x = arcsin(0) + π + 2nπ
… … … … … ==> 5x = 2nπ or 5x = (2n + 1)π
… … … … … ==> x = 2nπ/5 or x = (2n + 1)π/5
sin(2x) = 0 ==> 2x = arcsin(0) + 2nπ or 2x = arcsin(0) + π + 2nπ
… … … … … ==> 2x = 2nπ or 2x = (2n + 1)π
… … … … … ==> x = nπ or x = (2n + 1)π/2
cos(2x) = -1/2 ==> 2x = arccos(-1/2) + 2nπ or 2x = -arccos(-1/2) + 2nπ
… … … … … … ==> 2x = 2π/3 + 2nπ or 2x = -2π/3 + 2nπ
… … … … … … ==> x = π/3 + nπ or x = -π/3 + nπ
(where n is any integer)
Suppose A is the sum of the first 50 consecutive multiples of 3, and B is the sum of the first 50 consecutive multiples of 6. What percent of A is B ?
E. 50%
F. 75%
G. 100%
H. 200%
The correct answer is H. B is the 200% of A.
Since A is the sum of the first 50 multiples of 3, while B is the sum of the first 50 multiples of 6, to determine what percentage of A is B, the base numbers of both calculations must be considered, that is, 3 and 6. Thus, since 6 is 200% of 3 (6/3 = 2), B is 200% of A.
Learn more about percentages in https://brainly.com/question/18925632.
Which expression is equivalent to the given expression?
Answer:
Option C, a³b
Step-by-step explanation:
(ab²)³/b⁵
= a³b⁶/b⁵
= a³b
Answered by GAUTHMATH
Assume the sample is a random sample from a distribution that is reasonably normally distributed and we are doing inference for a sample mean
(a) Find endpoints of a t-distribution with 5 % beyond them in each tail if the sample has size n = 12.
(b) Find endpoints of a t-distribution with 1% beyond them in each tail if the sample has size n=20.
Answer:
a) Hence the endpoints of a t-distribution with 5% beyond them in each tail if the sample has size n=12 is ± 1.796.
b) Hence the endpoints of a t-distribution with 1% beyond them in each tail if the sample has size n=20 is ± 2.539.
Step-by-step explanation:
Here the answer is given as follows,
Frances bought a new dress that was discounted by 24%. she used the following expressions to find the price of the dress after the discount was applied
Answer:
[tex]0.76d[/tex]
Step-by-step explanation:
Given
[tex]Formula = d - (0.24)d[/tex]
Required
Equivalent expression
We have:
[tex]Formula = d - (0.24)d[/tex]
Open bracket
[tex]Formula = d - 0.24d[/tex]
[tex]Formula = 0.76d[/tex]
Select the expression that has a value of 13.
9 + 3 x (2 ÷ 3) + 6
(9 + 3) x 2 ÷ 3 + 6
9 − (3 x 2) ÷ 3 + 6
(9 + 3 x 2) ÷ 3 + 6
Answer:
9 − (3 x 2) ÷ 3 + 6 is the answer
A student determines the density of a chunk of metal to be 5.1 g/cm3. She then repeats the measurement four more times on the same chunk of metal and obtains values of 5.0, 4.9, 5.4, and 5.2 g/cm3 for the density. What is the standard deviation of the five measurements?
A. 0.148
B. 0.19
C. 0.037
D. 0.22
E. 0.17
Answer:
E. 0.17
Step-by-step explanation:
Mean:
Sum of all values divided by the number of values, so:
[tex]\overline{x} = \frac{5.1 + 5 + 4.9 + 5.4 + 5.2}{5} = 5.12[/tex]
Standard deviation:
Square root of the sum of the difference squared between each value and the mean, divided by the sample size, so:
[tex]s = \sqrt{\frac{(5.1-5.12)^2 + (5-5.12)^2 + (4.9-5.12)^2 + (5.4-5.12)^2 + (5.2-5.12)^2}{5}} = 0.172[/tex]
Thus the correct answer is given by option E.
Solve For X: 12 * X+3=51
Answer:
x=4
Step-by-step explanation:
12 * X+3=51
Subtract 3 from each side
12x +3-3 = 51-3
12x = 48
Divide by 12
12x/12 = 48/12
x = 4
The doubling time for an investment is 7.5 yeas. Find an exponential model for the growth of your money. Then find how long will take your investment to grow by factor of 5(Assume that you make an investment P)
Answer:
The correct answer is "17.414 years".
Step-by-step explanation:
Given:
Doubling time,
= 7.5 years
As we know,
[tex]P(t) = P_oe^{rt}[/tex]
now,
⇒ [tex]2P_o=P_o e^{r\times 7.5}[/tex]
[tex]2 = e^{r\times 7.5}[/tex]
[tex]r = \frac{ln2}{7.5}[/tex]
[tex]=0.092[/tex]
[tex]=9.2[/tex]%
then,
⇒ [tex]P(t) = P_o e^{0.092 t}[/tex]
here,
[tex]P(t) = 5P_o[/tex]
hence,
⇒ [tex]5P_o = P_o e^{0.092 t}[/tex]
[tex]e^{0.092t}=5[/tex]
[tex]t = \frac{ln5}{0.092}[/tex]
[tex]=17.414 \ years[/tex]
Answer:
The correct answer is "17.414 years".
Step-by-step explanation:
Valerie set out to bicycle from TBLS to the beach, a distance of 10 miles. After going a short while at 15 miles per hour, the bike developed a flat tire, and the trip had to be given up. The walk back to TBLS was made at a dejected 3 miles per hour. The whole episode took 48 minutes. How many miles from TBLS did the flat occur
Answer:
I think it is 3 miles becos the bicycle broke at 15miles per hour and the walk from the current place to the TBLS is 3 miles per hour
Write the point-slope form of an equation of the line through the points (-4, 7) and (5, 3).
Answer:
[tex]y-7=-\frac{\displaystyle 4}{\displaystyle 9}(x+4)[/tex]
OR
[tex]y-3=-\frac{\displaystyle 4}{\displaystyle 9}(x-5)[/tex]
Step-by-step explanation:
Hi there!
Point-slope form: [tex]y-y_1=m(x-x_1)[/tex] where [tex]m[/tex] is the slope and [tex](x_1,y_1)[/tex] is a point that falls on the line
1) Determine the slope (m)
[tex]m=\frac{\displaystyle y_2-y_1}{\displaystyle x_2-x_1}[/tex] where two given points are [tex](x_1,y_1)[/tex] and [tex](x_2,y_2)[/tex]
Plug in the given points (-4, 7) and (5, 3):
[tex]m=\frac{\displaystyle 3-7}{\displaystyle 5-(-4)}\\\\m=\frac{\displaystyle 3-7}{\displaystyle 5+4}\\\\m=\frac{\displaystyle -4}{\displaystyle 9}[/tex]
Therefore, the slope of the line is [tex]-\frac{\displaystyle 4}{\displaystyle 9}[/tex]. Plug this into [tex]y-y_1=m(x-x_1)[/tex] as [tex]m[/tex]:
[tex]y-y_1=-\frac{\displaystyle 4}{\displaystyle 9}(x-x_1)[/tex]
2) Plug a point into [tex]y-y_1=-\frac{\displaystyle 4}{\displaystyle 9}(x-x_1)[/tex]
[tex]y-y_1=-\frac{\displaystyle 4}{\displaystyle 9}(x-x_1)[/tex]
Because we're given two points, there are two ways we can write this equation:
[tex]y-y_1=-\frac{\displaystyle 4}{\displaystyle 9}(x-x_1)\\\\y-7=-\frac{\displaystyle 4}{\displaystyle 9}(x-(-4))\\\\y-7=-\frac{\displaystyle 4}{\displaystyle 9}(x+4)[/tex]
OR
[tex]y-3=-\frac{\displaystyle 4}{\displaystyle 9}(x-5)[/tex]
I hope this helps!
∫dx/(x+√(x^{2} +x+1)
Answer:
es1433
Step-by-step explanation:
Find the missing numerator: 3 1/3 = x/6
[tex]\sf\huge\underline\color{pink}{༄Answer:}[/tex]
[tex]\tt3 \frac{1}{3} = \frac{x}{6} \\ = \tt \frac{10}{3} = \frac{x}{6} \\ = \tt \frac{x}{6} = \frac{10}{3} \\ = \tt6 \frac{x}{6} = 6( \frac{10}{3} ) \\ = \tt\large\boxed{\tt{\color{pink}{x = 20}}}[/tex]
[tex]\color{pink}{==========================}[/tex]
#CarryOnLearning
I need answering ASAP please
Answer:
The choose (D) 1/3
I hope I helped you^_^
What's the slope and y-intercept of the equation 4x + 2y = 8?
Question 13 options:
m = –2; b = –4
m = 2; b = 4
m = –2; b = 4
m = 2; b = –4
Answer:
m= - 2, b = 4
Step-by-step explanation:
structure of a linear equation
y = mx + c
m = gradient / slope
c = intercept
convert the given equation according to this structure of linear equations
4x+2y = 8
2y = -4x + 8
y = -2x +4
according to this intercept is 4 and slope is -2
Set up and evaluate the integral that gives the volume of the solid formed by revolving the region bounded by y=x^8 and y = 256 in the first quadrant about the y-axis.
Using the shell method, the volume integral would be
[tex]\displaystyle 2\pi \int_0^2 x(256-x^8)\,\mathrm dx[/tex]
That is, each shell has a radius of x (the distance from a given x in the interval [0, 2] to the axis of revolution, x = 0) and a height equal to the difference between the boundary curves y = x ⁸ and y = 256. Each shell contributes an infinitesimal volume of 2π (radius) (height) (thickness), so the total volume of the overall solid would be obtained by integrating over [0, 2].
The volume itself would be
[tex]\displaystyle 2\pi \int_0^2 x(256-x^8)\,\mathrm dx = 2\pi \left(128x^2-\frac1{10}x^{10}\right)\bigg|_{x=0}^{x=2} = \boxed{\frac{4096\pi}5}[/tex]
Using the disk method, the integral for volume would be
[tex]\displaystyle \pi \int_0^{256} \left(\sqrt[8]{y}\right)^2\,\mathrm dy = \pi \int_0^{256} \sqrt[4]{y}\,\mathrm dy[/tex]
where each disk would have a radius of x = ⁸√y (which comes from solving y = x ⁸ for x) and an infinitesimal height, such that each disk contributes an infinitesimal volume of π (radius)² (height). You would end up with the same volume, 4096π/5.
The volume of the solid formed by revolving the region bounded by y=x^8 and y = 256 in the first quadrant about the y-axis is 4096π/5 cubic units.
What is integration?It is defined as the mathematical calculation by which we can sum up all the smaller parts into a unit.
We have a function:
[tex]\rm y = x^8[/tex] or
[tex]x = \sqrt[8]{y}[/tex]
And y = 256
By using the vertical axis of rotation method to evaluate the volume of the solid formed by revolving the region bounded by the curves.
[tex]\rm V = \pi \int\limits^a_b {x^2} \, dy[/tex]
Here a = 256, b = 0, and [tex]x = \sqrt[8]{y}[/tex]
[tex]\rm V = \pi \int\limits^{256}_0 {(\sqrt[8]{y}^2) } \, dy[/tex]
After solving definite integration, we will get:
[tex]\rm V = \pi(\frac{4096}{5} )[/tex] or
[tex]\rm V =\frac{4096}{5}\pi[/tex] cubic unit
Thus, the volume of the solid formed by revolving the region bounded by y=x^8 and y = 256 in the first quadrant about the y-axis is 4096π/5 cubic units.
Learn more about integration here:
brainly.com/question/18125359
The lengths of the parallel sides of
a trapezium are 12cm and 26cm
If Its area is 228cm square Find the
perpendicular distance between the
Parallel sides
Answer:
12 cm
Step-by-step explanation:
12+26/2 ×x =228
19x =228
X=12cm
If you were to place $2,500 in a savings account that pays 3% interest
compounded continuously, how much money will you have after 5 years?
Assume you make no other deposits or withdrawals.
Answer:
$2904.59
Step by Step Explanation:
2^17+2^14 chia hết cho 9
Step-by-step explanation:
không khó lắm đâu ._.._.._.
Convert the improper fraction to a whole or mixed number. (Enter your answer as a simplified mixed number.)
25
7
Dylan has a coworker who is always showing up late and then not finishing his work on time. It's frustrating the other members of the team. What can he do that might help the situation? a) Complain about the coworker to other team members O b) Ask his coworker if he understands his job responsibilities c) Tell his boss that the coworker is slacking off O d) Complete his coworker's work for him
A duck has 1,100 feathers. It went for a swim in a pond and lost 2/100 of its feathers. How many feathers did it lose?
Answer:
It lost 22 feathers.
Step-by-step explanation:
To complete this problem, this expression will be used: 2x/100.
2(1100)/100 {Multiply 2 by 1100}
2200/100 {Simplify by cancelling out 100}
22/1 {Divide}
22 feathers were lost.
a store sells pencils pens and markers that sells two times as many markers as pencils and three times as many pens as pencils is the store sells a total of 1950 pencils and pens and markers in a week how many of each were sold
Answer:
325 pencils, 650 markers, 975 pens
Step-by-step explanation:
in picture.
Need help please ^-^
Factored form: (x + 1/5)(x + 1/4)
Foil: x^2 + 1/4x + 1/5x + 1/20
Simplify: x^2 + 9/20x + 1/20
Hope this helps!
In the given figure L1and L2 are two parallel sides . if the area of the rectangle PQRS is 60cm^2 then what is the area of the parallelogram PQRS.
Answer:
Step-by-step explanation:
Believe it or not, the two areas are the same.
The base of the rectangle is PQ
The height of the rectangle is PS
Now look at the parallelogram.
The base is PQ
The height is PS
The area has to be the same in both cases. There is no other way to interpret what is happening.
PLEASE HELP!!!
Find the equation of the line with an x intercept of 4 and a y intercept of -1.5
Answer:
y = 4x - 1.5
Step-by-step explanation:
The slope intercept form of a line is
y = mx+b where m is the slope and b is the y intercept
y = 4x - 1.5
The scores on an entrance exam to a university are known to have an approximately normal distribution with mean 65% and standard deviation 7.1%. Using the normalcdf function on your graphing calculator, what percentage of students would score 70 or better on this entrance exam?
A. 28.4%
B. 18.9%
C. 24.1%
D. 22.3%
Answer:
The correct answer is - C. 24.1%
Step-by-step explanation:
Given:
mean μ = 65%
standard deviation δ = 7.1 %
solution:
Prob( X>70) = 1 - Prob(x<70)
= P (x-μ/δ ≥ 70 -65/7.1)
= 1 - Prob( (70-65)/7.1)
= 1 - Prob ( z < 0.7042553)
= 0.24065
the percentage of students scoring 70 or more in the exam
= 24.065*100
= 24.1%
PLZ ANSWER QUESTION IN PICTURE
Answer:
X-int = -5 and y-int = 6
Step-by-step explanation:
1.2x+6 = 0
1.2x= -6
X = -6/1.2
X = -5
Which phrase describes an unknown or changeable quality?
3 feet and 7 inches
4 quarts in a gallon
2 o'clock in the afternoon
The height of the building times 1/2
Answer:
it should be the height of the building time 1/2
Step-by-step explanation:
let me know if its correct or incorrect we'll I hope this help you
Suppose you like to keep a jar of change on your desk. Currently, the jar contains the following: 2323 Pennies 55 Dimes 2020 Nickels 1919 Quarters Copy Data What is the probability that you reach into the jar and randomly grab a dime and then, without replacement, a nickel
Answer:
The answer is "0.081"
Step-by-step explanation:
Dimes [tex]= 55[/tex]
Calculating total coins [tex]= (23+55+20+19) = 117[/tex]
P(for a dime) [tex]= \frac{55}{117}[/tex]
Calculating remaining coins [tex]= 116[/tex]
Nickels [tex]= 20[/tex]
P(for nickel draw in second) [tex]= \frac{20}{116}[/tex]
P(for a dime after that a nickel, without replacement)
[tex]= \frac{55}{117} \times \frac{20}{116} \\\\= \frac{1100}{13572} \\\\=0.081[/tex]
HELP ASAP! Can someone please help me with this problem. I tried inputting the numbers to find the mean but I did not get the right answer. Can someone please help me with the last box? Thank you for your time!
Answer:
try 17.6
Step-by-step explanation:
for the mean you have to add all the numbers then divide the sum by the total number of numbers you added
