It looks like you have to find the value of the sum,
[tex]C = \displaystyle \frac1{21\times22\times23} + \frac1{22\times23\times24} + \cdots + \frac1{200\times201\times202}[/tex]
so that the n-th term in the sum is
[tex]\dfrac1{(21+(n-1))\times(21+n)\times(21+(n+1))} = \dfrac1{(n+20)(n+21)(n+22)}[/tex]
for 1 ≤ n ≤ 180.
We can then write the sum as
[tex]\displaystyle C = \sum_{n=1}^{180} \frac1{(n+20)(n+21)(n+22)}[/tex]
Break up the summand into partial fractions:
[tex]\dfrac1{(n+20)(n+21)(n+22)} = \dfrac a{n+20} + \dfrac b{n+21} + \dfrac c{n+22}[/tex]
Combine the fractions into one with a common denominator and set the numerators equal to one another:
[tex]1 = a(n+21)(n+22) + b(n+20)(n+22) + c(n+20)(n+21)[/tex]
Expand the right side and collect terms with the same power of n :
[tex]1 = a(n^2+43n+462)+b(n^2+42n+440) + c(n^2+41n + 420) \\\\ 1 = (a+b+c)n^2 + (43a+42b+41c)n + 462a+440b+420c[/tex]
Then
a + b + c = 0
43a + 42b + 41c = 0
462a + 440b + 420c = 1
==> a = 1/2, b = -1, c = 1/2
Now our sum is
[tex]\displaystyle C = \sum_{n=1}^{180} \left(\frac1{2(n+20)}-\frac1{n+21}+\frac1{2(n+22)}\right)[/tex]
which is a telescoping sum. If we write out the first and last few terms, we have
C = 1/(2×21) - 1/22 + 1/(2×23)
… … + 1/(2×22) - 1/23 + 1/(2×24)
… … + 1/(2×23) - 1/24 + 1/(2×25)
… … + 1/(2×24) - 1/25 + 1/(2×26)
… … + … - … + …
… … + 1/(2×198) - 1/199 + 1/(2×200)
… … + 1/(2×199) - 1/200 + 1/(2×201)
… … + 1/(2×200) - 1/201 + 1/(2×202)
Notice the diagonal pattern of underlined and bolded terms that add up to zero (e.g. 1/(2×23) - 1/23 + 1/(2×23) = 1/23 - 1/23 = 0). So, like a telescope, the sum collapses down to a simple sum of just six terms,
C = 1/(2×21) - 1/22 + 1/(2×22) + 1/(2×201) - 1/201 + 1/(2×202)
which we simplify further to
C = 1/42 - 1/44 - 1/402 + 1/404
C = 1,115/1,042,118 ≈ 0.00106994
What is the area of the following circle?
Answer:
[tex]16\pi\:\mathrm{units^2}\text{ or }50.24\:\mathrm{ units^2}[/tex]
Step-by-step explanation:
The area of a circle with radius [tex]r[/tex] is given as [tex]A=r^2\pi[/tex].
In the question, we're given [tex]r=4[/tex] and asked to solve for [tex]A[/tex].
Substituting [tex]r=4[/tex] into [tex]A=r^2\pi[/tex], we get:
[tex]A=4^2\pi,\\A=\boxed{16\pi\:\mathrm{units^2}}[/tex]
If we use [tex]\pi=3.14[/tex] as mentioned in the question, we would have:
[tex]A=16\pi=16\cdot 3.14=\boxed{50.24\:\mathrm{units^2}}[/tex]
please find y and round to the nearest tenth
If you get it right, you are a critical thinker. You were in the garden, there are 34 people in the yard. You kill 30. How many people are in the garden?
Guys please help me solve this I’m struggling
Answer:
[tex]Max\ z = 1[/tex]
[tex]Min\ z = -9[/tex]
Step-by-step explanation:
Given
[tex]z = 4x + 5y[/tex]
[tex]x \ge -1[/tex]
[tex]y \le 2x +3[/tex]
[tex]y \le -1[/tex]
Required
The maximum and minimum of z
To do this, we make use of the graphical method
See attachment for graphs of
[tex]x \ge -1[/tex]
[tex]y \le 2x +3[/tex]
[tex]y \le -1[/tex]
The corner points of the function are:
[tex](x,y) = (-1,1)[/tex]
[tex](x,y) = (-1,0)[/tex]
[tex](x,y) = (-1,-1)[/tex]
We have:
[tex]z = 4x + 5y[/tex]
Calculate z with the above values
[tex]z = 4(-1) + 5(1) = 1[/tex]
[tex]z = 4(-1) + 5(0) = -4[/tex]
[tex]z = 4(-1) + 5(-1) = -9[/tex]
So, we have:
[tex]Max\ z = 1[/tex]
[tex]Min\ z = -9[/tex]
Please help explanation if possible
Answer:
y=-11
Step-by-step explanation:
A line can be represented by a linear equation of
[tex]y = mx + b[/tex]
where m is the slope and y is the y intercept.
The slope is 0 so this function will be
[tex]y = b[/tex]
Which is also called a constant function. The y intercept is -11. So the answer is
[tex]y = - 11[/tex]
if you can type 55 words in 20 seconds how long would it take to type 1,007 words
Answer:
2769.25Secound...........
The graph below shows the solution to which system of inequalities
Helpppp
Answer:
Step-by-step explanation:
Mike and Ken shared some stamps. \frac{1}{5} 5 1 of Ken's stamps were \frac{1}{3} 3 1 of Mike's stamps. If Mike gave Ken 24 stamps, Ken would have thrice as many stamps as Mike. Find the number of stamps each of them had in the beginning.
Answer:
Mike had 72 stamps
Ken had 120 stamps
Step-by-step explanation:
Given
[tex]M \to Mike[/tex]
[tex]K \to Ken[/tex]
[tex]\frac{1}{5} * K = \frac{1}{3} * M[/tex]
[tex]K + 24 = 3 * ( M - 24)[/tex]
Required
Find K and M
Make K the subject in: [tex]K + 24 = 3 * ( M - 24)[/tex]
[tex]K = 3 * ( M - 24) - 24[/tex]
Substitute [tex]K = 3 * ( M - 24) - 24[/tex] in [tex]\frac{1}{5} * K = \frac{1}{3} * M[/tex]
[tex]\frac{1}{5} * [3 * ( M - 24) - 24] = \frac{1}{3} * M[/tex]
Open brackets
[tex]\frac{1}{5} * [3M - 72 - 24] = \frac{1}{3} * M[/tex]
[tex]\frac{1}{5} * [3M -96] = \frac{1}{3} * M[/tex]
Multiply both sides by 15
[tex]3* [3M -96] = 5 * M[/tex]
[tex]9M -288 = 5M[/tex]
Collect like terms
[tex]9M -5M= 288[/tex]
[tex]4M= 288[/tex]
Divide both sides by 4
[tex]M= 72[/tex]
Substitute [tex]M= 72[/tex] in [tex]K = 3 * ( M - 24) - 24[/tex]
[tex]K = 3 * (72 - 24) - 24[/tex]
[tex]K = 3 * 48 - 24[/tex]
[tex]K = 120[/tex]
What type of conic section is the following equation?
5x^2-y=12
Answer:
The conic section for the equation 5x^2 - y = 12 is parabola
arc length of an oval that is 6ft by 5ft. i just want 1/4 of the oval. i want to find out how long i would need a wire to go from the ground to the middle of the "dome".
the picture explains it better.
in the end i want to have a wire frame around the garden and than take some netting and use that to keep out the big bugs and birds. i will of course use zip ties to attach the screen/netting to the frame. unless there is a easier and cheaper way to do this.
You can model the ellipse with the equation
(x/6)² + (y/5)² = 1
If you're comfortable with calculus, read on.
Let x = 6 cos(t ) and y = 5 sin(t ), with 0 ≤ t ≤ π/2. Then the curve C parameterized by (x(t), y(t)) traces out one quarter of the ellipse. The arc length of this curve is given by the integral,
[tex]\displaystyle\int_C\mathrm ds = \int_0^{\pi/2}\sqrt{x'(t)^2+y'(t)^2}\,\mathrm dt \\\\ = \int_0^{\pi/2}\sqrt{36\sin^2(t)+25\cos^2(t)}\,\mathrm dt \\\\ = \int_0^{\pi/2}\sqrt{25+11\sin^2(t)}\,\mathrm dt \\\\ = 5\int_0^{\pi/2}\sqrt{1+\frac{11}{25}\sin^2(t)}\,\mathrm dt[/tex]
Unfortunately, you cannot find the exact value of this integral. (Well, you can, but it involves introducing a special kind of function; I'll link it in a comment.)
But you can approximate it, and the integral above comes out to about 8.657.
I'm not sure if there's a simpler, purely geometric way to estimate the arc length. But since the semiaxes (5 ft and 6 ft) are fairly close, you could try a circle with a radius somewhere in between. The arc length would range between 7.854 ft and 9.425 ft. If the material isn't too expensive, you can always overshoot and trim off the excess or repurpose it.
(12, 9, 4) What is the area of the parallelogram shown below?
area of the parallelogram is: b x h
12 x 4 = 48 (d)
what is the slope of the line?
The slope is -1.
You have to find the two closest points where the line directly hits a number. For that, we have -3 in the first quadrant and -3 in the third quadrant. With this info, the line goes down 3 times and to the right 3 times, The ratio would look like this: [tex]\frac{-3}{3}[/tex]. Divide both and you get -1. Hope that helped!
Chocolate beans are packed in 250 g and 750 g packages. The number of 250 g packages and 750 g packages are in the ratio 1 : 2. If two of the 750 g packages are replaced into 250 g packages, then the ratio becomes 5 : 3. Find
a) the original number of 250 g packages,
b) the total mass of the chocolate beans.
Answer:
a) 4 packages
b) 7000 g or 7 kg
Step-by-step explanation:
x is the number of 250g packages and y is the number of 750g packages.
2x = y
3(x + 2 x (750 : 250)) = 5(y - 2)
3(x + 6) = 5(y - 2)
3(x + 6) = 5(2x - 2)
3(x + 6) = 5(2(x - 1))
3(x + 6) = 5 * 2 * (x - 1)
3(x + 6) = 10(x - 1)
3x + 18 = 10x - 10
(3x + 18) + 10 = (10x - 10) + 10
3x + 28 = 10x
28 = 10x - 3x
28 = 7x
x = 28/7
x = 4
y = 2 * 4 = 8
(250 * 4) + (750 * 8) = 7000 g
multiply
12/18×10/18
lesson name fraction.
find me out this question for answer
Independent Practice
Find the first, fourth, and eighth terms of the sequence.
an=0.5 · 3n−1a subscript n baseline equals 0.5 times 3 superscript n minus 1 baseline
A.
0.667; 4.5; 364.5
B.
3; 0.375; 0.0234375
C.
0.5; 13.5; 1093.5
D.
0.5; 121.5; 280.5
Answer:
C.
0.5; 13.5; 1093.5
Step-by-step explanation:
. Ram solved 2/7 part of an exercise while Shyam solved 1/5 of it. Who solved greater part and by how much?
fast please
Step-by-step explanation:
LCM of 7 and 5 is 35
now will make the denominator equal,
10+7/35
So, Ram's work = 10/35
Shyam's work = 7/35
so
Ram > Shyam
hope it helps
The weekly wages of employees of Volta gold are normally distributed about a mean of$1250 with a standard deviation of $120. Find the probability of an employee having a weekly wage lying 1) between $1320 and $970 2) over $1290 3) under $1400
Answer:
1) 0.7104 = 71%
2) 0.6615 = 66%
3) 0.8944 = 89%
Step-by-step explanation:
1)
Z(low)=-2.333 0.009815329
Z(upper)=0.583 0.720165536
2)
Z(low)=0.333 0.63055866
Z(upper)=8322.908 1
3)
Z(low)=-10.417 0
Z(upper)=1.25 0.894350226
If the blue radius below is perpendicular to the chord AC which is. 14 units long, what is the length of the segment AB?
Answer:
C. 7 units
Step-by-step explanation:
The given parameters are;
The length of the chord of the circle, [tex]\overline{AC}[/tex] = 14 units
The orientation of the radius and the chord = The radius is perpendicular to the chord
We have in ΔAOC, [tex]\overline{AO}[/tex] = [tex]\overline{OC}[/tex] = The radius of the circle
[tex]\overline{OB}[/tex] ≅ [tex]\overline{OB}[/tex] by reflexive property
The angle at point B = 90° by angle formed by the radius which is perpendiclar to the chord [tex]\overline{AC}[/tex]
ΔAOB and ΔCOB are right triangles (triangles having one 90° angle)
[tex]\overline{AO}[/tex] and [tex]\overline{OC}[/tex] are hypotenuse sides of ΔAOB and ΔCOB respectively and [tex]\overline{OB}[/tex] is a leg to ΔAOB and ΔCOB
Therefore;
ΔAOB ≅ ΔCOB, by Hypotenuse Leg rule of congruency
Therefore;
[tex]\overline{AB}[/tex] ≅ [tex]\overline{BC}[/tex] by Congruent Parts of Congruent Triangles are Congruent, CPCTC
[tex]\overline{AB}[/tex] = [tex]\overline{BC}[/tex] by definition of congruency
[tex]\overline{AC}[/tex] = [tex]\overline{AB}[/tex] + [tex]\overline{BC}[/tex] by segment addition postulate
∴ [tex]\overline{AC}[/tex] = [tex]\overline{AB}[/tex] + [tex]\overline{BC}[/tex] = [tex]\overline{AB}[/tex] + [tex]\overline{AB}[/tex] = 2 × [tex]\overline{AB}[/tex]
∴ [tex]\overline{AB}[/tex] = [tex]\overline{AC}[/tex]/2
[tex]\overline{AB}[/tex] = 14/2 = 7
[tex]\overline{AB}[/tex] = 7 units.
Answer:
7 units
Step-by-step explanation:
anyone can help me with this
Answer:
4x-7=-5x²
or, 5x²+4x-7=0
so the standard form of the equation is,
5x²+4x-7=0
or, f(x) = 5x²+4x-7
Answered by GAUTHMATH
If two triangles are congruent, which of the following statements must be
true? Check all that apply.
A. The corresponding sides of the triangles are congruent.
B. The triangles have the same shape.
DC. The triangles have the same size.
D. The corresponding angles of the triangles are congruent.
Answer:
the answer is a and ik because I just had the test
The length of a rectangle is 10 m more than its breadth. If the perimeter of rectangle is 80 m, find the dimensions of the rectangle.
if you like my answer then please mark me as brainliest
cho x,y thuộc n thoả mãn x hia 3 dư 1,y chia 3 dư 2.hỏi x.y chia 3 có số dư bằng bao nhiêu
Answer:
2
Step-by-step explanation:
x÷3 dư 1-->x=3a+1
y÷3 dư 2-->y=3b+2
x×y=(3a+1)×(3b+2)
=9ab+6a+3b+2
Mà 9ab, 6a, 3b chia hết cho 3, 2 chia 3 dư 1
==>x×y chia 3 dư 2
Out of a sample of 327 Americans, 245 said they had no interest in professional soccer.
(Data simulated from Carey & Kereslidze, 2007) A 95% confidence interval for the
proportion of Americans who have no interest in professional soccer is 0.70 to 0.80.
Suppose that another sample of 784 Americans was taken and asked the same question.
How would the width of the new confidence interval compare to the width of the
confidence interval based on the 327 women in the armed forces?
The width of the confidence interval based on the 784 women would be narrower than the
confidence interval based on the 327 women.
The width of the confidence interval based on the 784 women would be wider than the
confidence interval based on the 327 women.
The width of the confidence interval based on the 784 women would be the same as the
confidence interval based on the 327 women.
O No answer text provided.
Answer:
The width of the confidence interval based on the 784 women would be narrower than the confidence interval based on the 327 women.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.
[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
In which
z is the z-score that has a p-value of [tex]1 - \frac{\alpha}{2}[/tex].
The margin of error is:
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
From this, we have that the margin of error, and also the width, is inversely proportional to the sample size, that is, a larger sample size leads to a smaller margin of error and a narrower interval.
How would the width of the new confidence interval compare to the width of the confidence interval based on the 327 women in the armed forces?
New interval: 784
Old interval: 327
Sample size increased, so the new interval will be narrower, and the correct answer is:
The width of the confidence interval based on the 784 women would be narrower than the confidence interval based on the 327 women.
Solve for m g=4cm-3cm
Answer:
g/c =m
Step-by-step explanation:
g=4cm-3cm
Combine like terms
g = 1cm
g =cm
Divide by c
g/c = cm/c
g/c =m
A line with slope 3 intersects a line with slope 5 at the point (10, 15). What is the distance between the x-intercepts of these two lines?
Answer:
2
y = 3x-15
y=5x-35
x1=5
x2=7
distance between = 7-5 = 2
Step-by-step explanation:
30 Points cuz I need help ASAP
Answer:
the answer is option 1
Step-by-step explanation:
the negative angle => a quarter round angle (clockwise) = ¼ x ( -360°) = -90°
and
the positive angle => a full round angle + 270° = (360°)+270°
= 630°
Answer:
correct answer is -90 and 630
Step-by-step explanation:
A recipe for 4 servings requires salt and pepper to be added in the ratio of 2:3. If the recipe is adjusted from 4 to 8 servings, what is the ratio of salt and pepper that must now be added
Answer:
Is this a trick question ???
Why would the ratio of salt to pepper change if you doubled the recipe?
The amount of salt and pepper would double, but not the ratio...
the answer should be 2:3
Step-by-step explanation:
Tính : 2020^3-1/2020+2021
Answer:
2020³-1/4041
Step-by-step explanation:
which of the following is a tinomial
Given a line segment that contains the points A,B, & C in order,if AB = 2x + 3, BC = 4x - 11, and AC = 28, find the length of segment AB.
Answer:
15
Step-by-step explanation:
AB+BC=AC
2X+3+(4X-11)
6X-8=28
6x= 36
x=6
then ab= 2(6)+3
=15
bc= 4(6)-11
=13
ac=ab+bc
=15+13
=28
