Answer:
[tex]\sup(S) = 3[/tex].
[tex]\displaystyle \inf(S) = \frac{1}{3}[/tex].
Step-by-step explanation:
When factored, [tex]3\,x^{2} - 10\, x + 3[/tex] is equivalent to [tex](3\, x - 1)\, (x - 3)[/tex].
[tex]3\, x^{2} - 10\, x + 3 < 0[/tex] whenever [tex]\displaystyle x \in \left(\frac{1}{3},\, 3\right)[/tex].
Typically, the supremum and infimum of open intervals are the two endpoints. In this question, [tex]\sup(S) = 3[/tex] whereas [tex]\displaystyle \inf(S) = \frac{1}{3}[/tex].
Below is a proof of the claim that [tex]\sup(S) = 3[/tex]. The proof for [tex]\displaystyle \inf(S) = \frac{1}{3}[/tex] is similar.
In simple words, the supremum of a set is the smallest upper bound of that set. (An upper bound of a set is greater than any element of the set.)
It is easy to see that [tex]3[/tex] is an upper bound of [tex]S[/tex]:
For any [tex]x > 3[/tex], [tex]3\,x^{2} - 10\, x + 3 > 0[/tex]. Hence, any number that's greater than [tex]3\![/tex] could not be a member [tex]S[/tex]. Conversely, [tex]3[/tex] would be greater than all elements of [tex]S\![/tex] and would thus be an upper bound of this set.To see that [tex]3[/tex] is the smallest upper bound of [tex]S[/tex], assume by contradiction that there exists some [tex]\epsilon > 0[/tex] for which [tex](3 - \epsilon)[/tex] (which is smaller than [tex]3\![/tex]) is also an upper bound of [tex]S\![/tex].
The next step is to show that [tex](3 - \epsilon)[/tex] could not be a lower bound of [tex]S[/tex].
There are two situations to consider:
The value of [tex]\epsilon[/tex] might be very large, such that [tex](3 - \epsilon)[/tex] is smaller than all elements of [tex]S[/tex].Otherwise, the value of [tex]\epsilon[/tex] ensures that [tex](3 - \epsilon) \in S[/tex].Either way, it would be necessary to find (or construct) an element [tex]z[/tex] of [tex]S[/tex] such that [tex]z > 3 - \epsilon[/tex].
For the first situation, it would be necessary that [tex]\displaystyle 3 - \epsilon \le \frac{1}{3}[/tex], such that [tex]\displaystyle \epsilon \ge \frac{8}{3}[/tex]. Let [tex]z := 1[/tex] (or any other number between [tex](1/3)[/tex] and [tex]3[/tex].)
Apparently [tex]\displaystyle 1 > \frac{1}{3} \ge (3 - \epsilon)[/tex]. At the same time, [tex]1 \in S[/tex]. Hence, [tex](3 - \epsilon)[/tex] would not be an upper bound of [tex]S[/tex] when [tex]\displaystyle \epsilon \ge \frac{8}{3}[/tex].With the first situation [tex]\displaystyle \epsilon \ge \frac{8}{3}[/tex] accounted for, the second situation may assume that [tex]\displaystyle 0 < \epsilon < \frac{8}{3}[/tex].
Claim that [tex]\displaystyle z:= \left(3 - \frac{\epsilon}{2}\right)[/tex] (which is strictly greater than [tex](3 - \epsilon)[/tex]) is also an element of [tex]S[/tex].
To verify that [tex]z \in S[/tex], set [tex]x := z[/tex] and evaluate the expression: [tex]\begin{aligned} & 3\, z^{2} - 10\, z + 3 \\ =\; & 3\, \left(3 - \frac{\epsilon}{2}\right)^{2} - 10\, \left(3 - \frac{\epsilon}{2}\right) + 3 \\ = \; &3\, \left(9 - 3\, \epsilon - \frac{\epsilon^{2}}{4}\right) - 30 + 5\, \epsilon + 3 \\ =\; & 27 - 9\, \epsilon - \frac{3\, \epsilon^{2}}{4} - 30 + 5\, \epsilon + 3 \\ =\; & \frac{3}{4}\, \left(\epsilon\left(\frac{16}{3} - \epsilon\right)\right)\end{aligned}[/tex].This expression is smaller than [tex]0[/tex] whenever [tex]\displaystyle 0 < \epsilon < \frac{16}{3}[/tex]. The assumption for this situation [tex]\displaystyle 0 < \epsilon < \frac{8}{3}[/tex] ensures that [tex]\displaystyle 0 < \epsilon < \frac{16}{3}\![/tex] is indeed satisfied. Hence, [tex]\displaystyle 3\, z^{2} - 10\, z + 3 < 0[/tex], such that [tex]z \in S[/tex].At the same time, [tex]z > (3 - \epsilon)[/tex]. Hence, [tex](3 - \epsilon)[/tex] would not be an upper bound of [tex]S[/tex].Either way, [tex](3 - \epsilon)[/tex] would not be an upper bound of [tex]S[/tex]. Contradiction.
Hence, [tex]3[/tex] is indeed the smallest upper bound of [tex]S[/tex]. By definition, [tex]\sup(S) = 3[/tex].
The proof for [tex]\displaystyle \inf(S) = \frac{1}{3}[/tex] is similar and is omitted because of the character limit.
find the value of a and b in (a,2)=(2,b)
Answer:
a=2 and b=2...............
What is the answer to |-2|+|-3|
Answer:
5
Step-by-step explanation:
the absolute value of -2 is 2
the absolute value of -3 is 3.
Since the question is adding the absolute values, the answer is 5
find the value of xand y : x=2y and x+y=6
Answer:
y=2 x=4
Step-by-step explanation:
Substitute x with 2y so the second equation is 2y+y=6
Then simplify your new equation:
3y=6
y=2
If y=2 and x=2( 2) then x=4
Solve (x - 2 < 5) ∩ (x + 7 > 6).
Ø
{x | x < -1 x < 7}
{x | -1 < x < 7}
x - 2 < 5 ⇒ x < 7
x + 7 > 6 ⇒ x > -1
Together, we have -1 < x < 7, which in set notation is
[tex]\left\{x \mid -1 < x < 7\right\}[/tex]
(third choice)
Peter pay $79.80 for returning a bicycle for 6 hours, what was the rate per hour
Answer:
$13.3 per hour
Step-by-step explanation:
for 6 hour the cost is $79.80
for 1 hour the cost is $79.80/6
$13.3 per hour
Sets question with option answers. Help please
Answer:
best bet is 6
Step-by-step explanation:
A man drove 13 miles directly east from his home, made a left turn at an intersection, and then traveled 9 miles due north to his place of work. If the road was made as described above, how much shorter would the man’s one-way trip be every day?
Answer:
ANSWER 5.3 miles
See IMAGE FOR SOLUTION
. Mr. Sheng is using a faucet attachment to fill the fish tank in his blology classroom. The graph below shows the amount of water in the
tank during the first several minutes since he turned on the faucet. What is the slope of a line joining the points on the graph? If your
answer is not an integer, express it as a decimal.
Answer:
8
Step-by-step explanation:
Slope = (change in y) / (change in x) = (y₂-y₁)/(x₂-x₁)
We have two points on the graph, (2, 16) and (6, 48)
Let's say (2, 16) = (x₁, y₁) ( there's no reason why (6, 48) can't be (x₁, y₁), but one of them has to be it) and (6, 48) = (x₂, y₂). Our slope is then
(y₂-y₁)/(x₂-x₁) = (48-16) / (6-2) = 32 / 4 = 8
Ruben needs to read 4 novels each month let N be the number of novels Ruben needs to read in M months write an equation relating in to M
Answer:
Step-by-step explanation:
N = 4(12) = 48 novels
1. If x = y and x + 2y = 6 then find value of 'y'.
T
Step-by-step explanation:
x=y
x+2y=6
y+2y=6
3y=6
y=2
Step-by-step explanation:
x=y
x+2y=6
y+2y=6
3y=6
y=2
Scores 18 20 16 13. Find this student's mean quiz score
Answer: 16.75
Step-by-step explanation:
Answer:
16.75
Step-by-step explanation:
To find the mean, add up all the number
18+20+16+13
67
Then divide by the number of quizzes
67/4
16.75
What is 1.7¯ expressed as a fraction in simplest form?
16/9.................
Answer:
16/9
Step-by-step explanation:
Ivan’s desserts made a batch of fresh scones with 4/5 of a pound of butter and 1/2 of a pound of sugar. How much more butter than sugar was used?
Help please due today
Answer:
Base: 24 and height:6
Step-by-step explanation:
Answer:
Base: 24
Height: 6
Step-by-step explanation:
The question says a scale factor of 1/2 so divide by 2. It says scale back
so you know as well that your answer is going to get bigger.
Original Base = 48/2 or (48)x(1/2)
Original Height = 12/2 or (12)x(1/2)
Solve 4.5 divided by 0.9
Answer:
4.5 / 9 = 1/2
The graph of f(x) = 3x + 8 is shown.
Which statement is true?
ТУ
3
f(x)
O The function is only increasing when x2-8.
O The function is only increasing when x 20.
O The function is always decreasing.
O The function is always increasing.
-16
-12
8
X
-2
3
Answer:
the function is always increasing
Step-by-step explanation:
if you look at the graph, as x increases, y increases, no matter how small the increase
3√12•√6
please show a step by step explanation
Answer: [tex]18\sqrt{2}\\\\[/tex]
This is the same as saying 18*sqrt(2) or you could say 18√2
============================================================
Explanation:
We'll be using this square root rule: [tex]\sqrt{A}*\sqrt{B} = \sqrt{A*B}[/tex]
So we could have this as our steps:
[tex]3\sqrt{12}*\sqrt{6}\\\\3\sqrt{12*6} \ \text{ ... Apply the rule mentioned}\\\\3\sqrt{72}\\\\3\sqrt{36*2}\\\\3\sqrt{36}*\sqrt{2} \ \text{ ... Apply the rule again, but in reverse}\\\\3*6*\sqrt{2}\\\\18\sqrt{2}\\\\[/tex]
Therefore, [tex]3\sqrt{12}*\sqrt{6} = 18\sqrt{2}[/tex]
The basic idea is to first combine the roots using that rule. From there, we factor the radicand such that we pull out the largest perfect square factor. This will allow us to break the root apart and fully simplify it.
Let f be a function defined on the set of positive rational numbers with the property that f(a · b) = f(a) + f(b) for all positive rational numbers a and b. Suppose that f also has the property that f(p) = p for every prime number p. For which of the following numbers x is f(x) < 0?
a. 17/32
b. 11/16
c. 7/9
d. 7/6
e. 25/11
Helpp
Ok I don’t know how they got 3y-24
Answer:
y = -5/3x + 3
Step-by-step explanation:
First lets turn the equation from standard form to slope intercept form.
3x - 5y = 1
~Subtract 3x to both sides
-5y = 1 - 3x
~Divide -5 to everything
y = -1/5 + 3/5x
~Reorder
y = 3/5x - 1/5
Now that we have the equation in slope intercept form, we can find the new equation. A perpendicular line will have the opposite reciprocal of the original slope.
3/5x -> -5/3x
Now that we have the slope, we can use the given point to find the y-intercept.
y = -5/3x + b
8 = -5/3(-3) + b
8 = 5 + b
3 = b
Put all the information we solved for into a final equation.
y = -5/3x + 3
Best of Luck!
You are designing a metal sculpture that will be placed in front of your school. You sketch an initial design
with a scale of 1 cm = 2 feet. The design shows that the sculpture has a length of 8 feet.
After reviewing your design, the principal asks you to use the same drawing, but change the scale to 1 cm
= 5 feet.
What will be the length of the sculpture using the new scale?
A. 8 feet
B. 12 feet
C. 15 feet
D. 20 feet
Using proportions, it is found that the length of the sculpture using the new scale is given by:
D. 20 feet.
What is a proportion?A proportion is a fraction of a total amount, and the measures are related using a rule of three.
The initial scale is of 1 cm = 2 feet, with a sculpture of 8 feet, hence the length of the drawing is given by:
l = 8/2 = 4 cm.
For the new scale, 1 cm = 5 feet, and you keep the drawing of 4 cm, hence the length of the sculpture is given by:
l = 4 x 5 = 20 feet.
Hence option D is correct.
More can be learned about proportions at https://brainly.com/question/24372153
#SPJ1
If the value of "y" varies directly with "x"
and y = -8 when x = 4.
Find "y" when x = -4
Answer:
Y=K×X
when Y=-8 and X=4
-8=K×4
-8=4K divide both sides by 4
K=-2 constant
To find Y when X=-4,Y=? and K=-2
Y=-2×-4
Y=8
Elementary algebra 1/4 divided by 3 equals
Answer:
1/12
Step-by-step explanation:
multiply by three so 4x3 is 12 and that's 3 equal parts
What is 50 divided by 8?
Answer:
6.25 or 6 2/8 or 6 R2
Step-by-step explanation:
A rental car agency charges $220 per week plus $0.15 per mile to rent a car. How many miles can you travel in one week for $352.00?
Answer:
880 miles
Step-by-step explanation:
352 - 220 = 132
132 ÷ 0.15 = 880
880 miles
Write a inequality please help.
a number is at least -43
Answer:
x≥ -43
Step-by-step explanation:
at least means greater than or equal to
Let x be the unknown number
x≥ -43
Find the y-intercept and x-intercept of the line. 5x-8y=14
Answer:
x-intercept = 14/5
y-intercept = 7/4
Step-by-step explanation:
To find the value of an intercept (x/y) of an equation like this, simply set the other variable to 0 and divide both sides by the coefficient of the variable you're trying to find.
Round 123,949 to the underlined point. 4 is highlighted
[tex]\\ \sf\longmapsto 123,949[/tex]
9 is greater than 5[tex]\\ \sf\longmapsto 123,95[/tex]
5=5[tex]\\ \sf\longmapsto 123,9[/tex]
9 is greater than 5[tex]\\ \sf\longmapsto 124[/tex]
4 is less than 5[tex]\\ \sf\longmapsto 12[/tex]
2 is less than 5[tex]\\ \sf\longmapsto 1[/tex]
Note
Write the number until underlined point.I did it till end
Answer:
The number is 123949 (or 123.949 in case comma stands for decimal)
According the rounding rule
if the number to the right is ≥ 5, round up the number to the left, otherwise leave as is, if decimal the number to the right drops, if whole number it is replaced with zeroRound to the number 4, the second number from the right:
123950or
123.95HELP PLS!! D:
The net of a rectangular prism is shown below. What is the total surface area of this prism?
A. 112 cm²
B. 142 cm²
C. 105 cm²
D. 71 cm²
=========================================================
Explanation:
Think of unwrapping a present and doing so without any unnecessary tearing. That means there aren't any little small pieces thrown away. There are many ways to unwrap a 3D box, and this diagram shows one of many ways. This flat layout is the 2D version of the 3D surfaces.
To find the surface area of the 3D figure, we simply need to find the area of each rectangle in this 2D flat net. Once we know all the little areas, we add them up to get the surface area.
------------------------------
The lowest rectangle is 3 cm by 5 cm, so its area is 3*5 = 15 cm^2. Let A = 15 so we can use it later.
Let's move to the middle row of four rectangles. From left to right, we have these four rectangular areas
3*7 = 21 cm^25*7 = 35 cm^23*7 = 21 cm^25*7 = 35 cm^2I'll call these results B,C,D,E in the order given above. So B = 21, C = 35, etc.
The rectangle up top has area of 3*5 = 15 cm^2. I'll let F = 15
Lastly, we'll add up the sub-areas to get the grand total
A+B+C+D+E+F = 15+21+35+21+35+15 = 142 cm^2 is the surface area
------------------------------
Another pathway to the answer:
If you can picture how this flat diagram would fold up, then you would see that we'd get a 3D block with the following dimensions
L = 7 cmW = 5 cmH = 3 cmThe order of L,W,H doesn't really matter.
Then we can use the 3D block surface area formula like so
SA = 2*(LW + LH + WH)
SA = 2*(7*5 + 7*3 + 5*3)
SA = 2*(35 + 21 + 15)
SA = 2*71
SA = 142 cm^2 is the surface area
As you can see from the third step, we have "35", "21" and "15" show up again. The 2 out front is because we have 2 copies of each item mentioned.
= Introduction to elapsed time Keiko started washing at 7:28 AM and finished at 8:46 AM. How long did it take her? Give your answer in hours and minutes. min X Х o ?
Answer:
Step-by-step explanation:
At 8:28 exactly one hour had gone by.
To get to 8:46 you need to add on almost 20 minutes. which would bring it up to 8:48. Since you are 2 minutes short from :46 to :48, the correct number of minutes is 18 (48 - 2)
Answer: 1 hour and 18 minutes.
supposed f(x) = 2x+5 what is the value of -2f(x+1)? PLEASE THIS IS THE LAST QUESTION ILL GIVE A BRAINLIEST
Answer:
-4x+1-10
Step-by-step explanation:
-2(2x+5)=0
-4x-10=0
-4x+1-10=0
-4x-9=0
-4x=9
x=9/-4
x=-2,25
please inform if wrong
