A swimming pool is treated periodically to control harmful bacteria growth.
The concentration of bacterial per cm³ after t days is given by
C(t)
[tex] = 30t^2 -240t + 500 [/tex]
in how many days after a treatment will be concentration be minimal ?
Answers
Answer:
The answer is 4
Step-by-step explanation:
[tex]c \: (t) = {30ft}^{2} = - 240t + 500[/tex]
For a quadratic function as given to find the minimum you need to write it in vertex or find the vertex (the vertex in a quadratic function is thr maximum or minimum).
Use the next formula to find the t coordinate of the vertex (the time in the minimum concentration of bateria):
[tex]c \: (t) = {at}^{2} + bt + c \\ \\ tm = - \frac{b}{2a} [/tex]
For the given function:
[tex]tm = - \frac{ - 240}{(2)30} = \frac{240}{60} = 4[/tex]
The minimum concentration of bacteria will be after 4 days.
Related Questions
Suppose John is a 14-year-old boy who weighs 45 kg (100 lbs). John is at the 25thpercentile of weight for his age. Twenty-five percent of 14-year-old boys weigh the same or less than John and 75% weigh more than John. If John’s height is 170 cm (almost 5’7”), he is at the 75thpercentile of his height for age. Based on the informationgiven about John, how would you describe John’s general appearance?
Answers
Simplify and leave in radical form.
Answers
Answer:
Step-by-step explanation:
Expressing in simplest radical form just means simplifying a radical so that there are no more square roots, cube roots, 4th roots, etc left to find. It also means removing any radicals in the denominator of a fraction.
mark me as brill
What is 15/12 simplifed?
Answers
Answer:
that is 5/4 to the lowest Terms
Answer:
1.25 or 1 1/4
Step-by-step explanation:
Used a calculator.
What are the ratios of sine, cosine, and tangent for angle Y? sin(Y) = StartFraction X Z Over X Y EndFraction; cos(Y) = StartFraction Y Z Over X Z EndFraction; tan(Y) = StartFraction Y Z Over X Y EndFraction sin(Y) = StartFraction X Y Over X Z EndFraction; cos(Y) = StartFraction X Z Over X Y EndFraction; tan(Y) = StartFraction Y Z Over X Z EndFraction sin(Y) = StartFraction X Z Over X Y EndFraction; cos(Y) = StartFraction Y Z Over X Y EndFraction; tan(Y) = StartFraction X Z Over Y Z EndFraction sin(Y) = StartFraction Y Z Over X Y EndFraction; cos(Y) = StartFraction X Z Over X Y EndFraction; tan(Y) = StartFraction X Z Over Y Z EndFraction
Answers
Answer:
[tex]\sin Y= \frac{XZ}{XY}[/tex]
[tex]\cos Y= \frac{YZ}{XY}[/tex]
[tex]\tan Y= \frac{XZ}{YZ}[/tex]
Step-by-step explanation:
Given
See attachment for triangle
Required
Find [tex]\sin, \cos[/tex] and [tex]\tan[/tex] of angle Y
For angle Y:
[tex]Opposite = XZ[/tex]
[tex]Adjacent = YZ[/tex]
[tex]Hypotenuse = XY[/tex]
The [tex]\sin[/tex] of an angle is calculated as:
[tex]\sin\theta = \frac{Opposite}{Hypotenuse}[/tex]
So:
[tex]\sin Y= \frac{XZ}{XY}[/tex]
The [tex]\cos[/tex] of an angle is calculated as:
[tex]\cos\theta = \frac{Adjacent}{Hypotenuse}[/tex]
So:
[tex]\cos Y= \frac{YZ}{XY}[/tex]
The [tex]\tan[/tex] of an angle is calculated as:
[tex]\tan\theta = \frac{Opposite}{Adjacent}[/tex]
So:
[tex]\tan Y= \frac{XZ}{YZ}[/tex]
Answer:
c
Step-by-step explanation:
.
Find the y-intercept of y - x = 7.
Answers
At practice, Diego does twice as many push-ups as Noah, and also 40 jumping
jacks. He does
62 exercises in total. The equation 2x + 40 =62 describes this situation. What does
the
variable represent?
Answers
Answer:
1980
Step-by-step explanation:
5x4*x9=1980
Hope this helps :)
Brainliest?
｡◕‿‿◕｡ ITS PICKACHU DAY
A cube has a volume of 64. What is the side length of one side
#15
Answers
Answer:
4
Step-by-step explanation:
volume is equal to a x a x a
This means that [tex]a^{3}[/tex] = V
Therefore, a = cube root of V, which is 4
Using the formula
V=a3
Solving fora
a=V⅓=64⅓≈4
Please help me question is in the picture
Answers
Answer:
1. Down
2. 9 units down
3. Left
4. 5 units left
The measure of EFH is twice the measure of GFH. What is the
degree measure of GFH?
I NEED HELP ASAP
Answers
Answer:
30° = m∠GFH
Step-by-step explanation:
Since ∠EFH and ∠GFH are complementary, the sum of their measures i 90.
Let x = m∠GFH
2x = m∠EFH
m∠GFH + m∠EFH = 90
x + 2x = 90
3x = 90
x = 30° = m∠GFH
Answer: 30
Step-by-step explanation: qu i z i zz
find the real zeros of k(x)= x^3 - 2x^2 +2x -4
Answers
Answer: k=x^3-2x^2+2x-4/x
Step-by-step explanation: hope this helps!
hi please answer this xoxo will mark brainliest
Answers
since isosceles has 2 sides that are equal then,
270 - 108 = 162
divide 162 by 2
162 ÷ 2 = 81
so, C
Answer:
A.)
Step-by-step explanation:
108 + 100 + 62 = 270
The length of adult King Cobra snakes is normally distributed with µ = 18 feet and σ = 2.1 feet. What is the probability that a randomly selected adult King Cobra snake be over 15.9 feet long? 85.54% 79.08% 15.87% 84.13%
Answers
Answer:
the probability that a randomly selected adult King Cobra snake be over 15.9 feet long is 84.13%
Step-by-step explanation:
The computation of the probability is shown below":
P(x>15.9) is
[tex]= P (\frac{x - \mu}{\sigma} > \frac{15.9 - 18}{2.1} )\\\\= P (z>-1)\\\\= 0.8413\\\\= 84.13\%[/tex]
Hence, the probability that a randomly selected adult King Cobra snake be over 15.9 feet long is 84.13%
We simply applied the above formula
Answer:
the probability that a randomly selected adult King Cobra snake be over 15.9 feet long which is 84.13%
Step-by-Step Explanation:
P(X 15.9). Solve for the z-score and then match it with the probability from the area under the normal curve table. Once that is found, take the complement or use symmetry to solve
Note:
Hope this helps you in the future.
Learn More:
https://brainly.com/question/6305087?referrer=searchResults
$1,000 at 7.5% for 30 months
Answers
Step-by-step explanation:
principal=1000
rate=7.5
time=30 moths
interest= principal multiplied to rate multiplied to time by 100
which give 100multiplied to 7.t multiplied to 30 by 10p
which gives 22500by 100
which gives 225
amount= interest plus principal
= 225+1000
=1225
The graph below shows a company's profit f(x), in dollars, depending on the price of goods x. in dollars, being sold by the
company:
Part A: What do the x-intercepts and maximum value of the graph represent?
Part B: What are the intervals
where the function is increasing and decreasing, and what do they represent about the sale and
profit?
Part C: What is an approximate average rate of change of the graph from x = 1 to x = 3, and what does this rate represent?
Answers
Answer:
What do the x-intercepts and maximum value of the graph represent? The x-intercepts represent the points at the ground, so with that you have the width of the tunnel at ground level is 120 ft - 0 ft = 120
Step-by-step explanation:
The table below shows the account value of each of Dmitri's three bank accounts
Dank account
Account value
Savings
8573.73
Retirement
8204.43
Checking
-$435.24
Help Dmitri sort his accounts from lowest to highest absolute value of account value. Click and drag to sort the
tiles
Checking
Retirement
Savings
Answers
Answer:
there could be more than one answer...
Step-by-step explanation:
Answer:
Retirement Checking Savings
Step-by-step explanation:
in that order(khan said so)
If i have 172 centimetres of ribbon to decorate a gift basket. How many more centimetres of ribbon would i need to make 3 metres
Answers
1 meter = 100 centimeters
3 meters = 300 centimeters
subtract 300 by 172
= 128 more centimeters
another question of the homework
Answers
Answer:
Jessica's trains travels at a faster speed
Step-by-step explanation:
From the question,
Using the graph,
The total distance distance traveled by Khalid after 2 hours is
d = 280 mi.
S = d/t....................... Equation 1
Where S = Khalid's speed, d = Khalid's distance, t = time.
S = 280/2
S = 140 mph.
From the euqation,
The total distance traveled by Jessica after 2 hours is
y = 150×2
y = 300 mi.
Also Using
S' = d'/t
Where S' = Jessica's speed, d' = Jessica's distance
S' = 300/2
S' = 150 mph.
From the above, Jessica's trains travels at a faster speed
cosec 45^0
= ______ .
Answers
Answer:
cosec45° = [tex]\sqrt{2}[/tex]
Step-by-step explanation:
Using the identity
cosec x = [tex]\frac{1}{sinx}[/tex] and the exact value
sin45° = [tex]\frac{1}{\sqrt{2} }[/tex]
Then
cosec45° = [tex]\frac{1}{\frac{1}{\sqrt{2} } }[/tex] = [tex]\sqrt{2}[/tex]
Using diagonals from a common vertex, how many triangles could be formed from a
24-gon?
Answers
Answer:
22 triangles in a 24-gon.
Step-by-step explanation:
24−2=22
There are 22 triangles in a 24-gon.
Answer:
13 triangles in a 15-gon
Step-by-step explanation:
15-2=13
What is the exact circumference of the circle?
Answers
Answer:
circumference = 22.2144 or 5π√2
Step-by-step explanation:
the diameter of the circle would be equal to the diagonal of the square.
Using the Pythagorean theorem:
D² = 5² + 5²
D² = 50
D = 7.0711 or 5√2
circumference = πD = 5π√2 = 22.2144
Answer:
diagonal or diameter =√(5²+5²)=5√2unit
therefore radius =5/2√2unit
circumference of circle =2πr=2×π×5/2×√2=5π√2unit
[tex]y= 82(1.045)[/tex]What is the rate of growth Michael expects each week after launching the website?
y=82(1.045)
Answers
Answer: pls help with the answer this is hard
Step-by-step explanation: i really need help!!!
URGET: Inscribed Angles
Find the measure of angle R.
Answers
Answer:
∠ R = 50°
Step-by-step explanation:
The inscribed angle R is half the measure of its intercepted arc QS
QS = 360° - (120 + 140)° = 360° - 260° = 100° , then
∠ R = 0.5 × 100° = 50°
This is a similar triangle please find the missing length. (?)
Answers
Answer:
33
Step-by-step explanation:
In ΔPQR,
length of side=
77= 7×11
84= 12
Similarly, In ΔFGH
length=
36=3×12
so, the other side= 3×11= 33
Answer:
33
Step-by-step explanation:
[tex]\frac{HG}{FG} =\frac{RQ}{PQ}[/tex], insert given values
[tex]\frac{?}{36}=\frac{77}{84}[/tex], cross multiply
84*?=36*77
84*?=2772, divide both sides by 84 to get ? by itself
?=33
PLEASE HELP ME I’LL GIVE BRILLIANCE TO YOU
Answers
Answer:
y=-2x+8
Step-by-step explanation:
y intercept is at 8, and there is a decrease in 2x per 1y
Answer:
the answer is the second one do nitrotype. com
Step-by-step explanation:
get rid of the space in .com
Frodo goes to New Army and buys two pairs of jeans for $19.99 each, 3 shirts at $7.99 each, and a pack of socks for $5. He has a
coupon for 25% off his entire purchase. Sales tax is 7 %. What is the total cost after the discount and tax? $
109points plsss helpppppp now
Answers
Answer:
lol i answered on another 1 of ur things
Quadrilateral ABCD is inscribed in a circle. Find the measure of each of the angles of the quadrilateral. Show
your work.
Answers
Answer:
A= 94°, B = 102°, C = 86°, D = 78°Step-by-step explanation:
ABCD is a cyclic quadrilateral
It has the property that opposite angles are supplementary: A with C and B with D.
Solve following for x:
x + 6 + x - 2 = 180°2x + 4 = 180°2x = 176°x = 88°The angles are:
A = 88° + 6° = 94°C = 180° - 94° = 86°D = 88° - 10° = 78°B = 180° - 78° = 102°Solve for X
Solve for X
Solve for X
Answers
Answer: it is 4
Step-by-step explanation:
Answer:
Opposite sides of the parallelogram are congruent
[tex]3x+4=16[/tex][tex]3x=16-4[/tex][tex]3x=12[/tex][tex]x=12/3[/tex][tex]x=4[/tex]------------------------hope it helps...have a great day!!Some students want to order shirts with their school logo, The Tees company charges $9.65 per shirt
plus a setup fee of $43. The Shirtz company charges $8.40 per shirt plus a $58 fee. Which company
would you recommend to the students?
Answers
Tee Company: 9.65x + 43
Shirtz Company: 8.40x + 58
If you were to buy one shirt from each company these would be the prices,
Tee Company: $52.65
Shirtz Company: $66.40
I would recommend the Tee Company since the price per shirt is cheaper.
What is the sum of the degree measures of the complement and the supplement of a 16° angle?
Answers
Answer:
270?
Step-by-step explanation:
180 + 90 = 270
Anne solved 5(2x−3)=20x+15 for x by first multiplying 5 and 2x on the left side of the equation. She got the answer x = −95. When she substituted −9/5 into the original equation her answer was incorrect. Explain Anne’s error, and find the correct answer.
Answers
Answer: x=-3
Step-by-step explanation:
Anne's error is that she only multiplies 5 and 2x on the left side, she needs to multiply 5 and 2x, and also that she needs to multiply 5 and -3.
5(2x−3)=20x+15
5(2x) + 5(-3) = 20x + 15
10x - 15 = 20x + 15
-10x - 15 = 15
-10x = 30
x = -3