Answer:
1302
Step-by-step explanation:
Let c be a positive number. A differential equation of the form dy/dt=ky^1+c where k is a positive constant, is called a doomsday equation because the exponent in the expression ky^1+c is larger than the exponent 1 for natural growth. An especially prolific breed of rabbits has the growth term My^1.01. If 2 such rabbits breed initially and the warren has 16 rabbits after three months, then when is doomsday?
Answer:
The doomsday is 146 days
Step-by-step explanation:
Given
[tex]\frac{dy}{dt} = ky^{1 +c}[/tex]
First, we calculate the solution that satisfies the initial solution
Multiply both sides by
[tex]\frac{dt}{y^{1+c}}[/tex]
[tex]\frac{dt}{y^{1+c}} * \frac{dy}{dt} = ky^{1 +c} * \frac{dt}{y^{1+c}}[/tex]
[tex]\frac{dy}{y^{1+c}} = k\ dt[/tex]
Take integral of both sides
[tex]\int \frac{dy}{y^{1+c}} = \int k\ dt[/tex]
[tex]\int y^{-1-c}\ dy = \int k\ dt[/tex]
[tex]\int y^{-1-c}\ dy = k\int\ dt[/tex]
Integrate
[tex]\frac{y^{-1-c+1}}{-1-c+1} = kt+C[/tex]
[tex]-\frac{y^{-c}}{c} = kt+C[/tex]
To find c; let t= 0
[tex]-\frac{y_0^{-c}}{c} = k*0+C[/tex]
[tex]-\frac{y_0^{-c}}{c} = C[/tex]
[tex]C =-\frac{y_0^{-c}}{c}[/tex]
Substitute [tex]C =-\frac{y_0^{-c}}{c}[/tex] in [tex]-\frac{y^{-c}}{c} = kt+C[/tex]
[tex]-\frac{y^{-c}}{c} = kt-\frac{y_0^{-c}}{c}[/tex]
Multiply through by -c
[tex]y^{-c} = -ckt+y_0^{-c}[/tex]
Take exponents of [tex]-c^{-1[/tex]
[tex]y^{-c*-c^{-1}} = [-ckt+y_0^{-c}]^{-c^{-1}[/tex]
[tex]y = [-ckt+y_0^{-c}]^{-c^{-1}[/tex]
[tex]y = [-ckt+y_0^{-c}]^{-\frac{1}{c}}[/tex]
i.e.
[tex]y(t) = [-ckt+y_0^{-c}]^{-\frac{1}{c}}[/tex]
Next:
[tex]t= 3[/tex] i.e. 3 months
[tex]y_0 = 2[/tex] --- initial number of breeds
So, we have:
[tex]y(3) = [-ck * 3+2^{-c}]^{-\frac{1}{c}}[/tex]
-----------------------------------------------------------------------------
We have the growth term to be: [tex]ky^{1.01}[/tex]
This implies that:
[tex]ky^{1.01} = ky^{1+c}[/tex]
By comparison:
[tex]1.01 = 1 + c[/tex]
[tex]c = 1.01 - 1 = 0.01[/tex]
[tex]y(3) = 16[/tex] --- 16 rabbits after 3 months:
-----------------------------------------------------------------------------
[tex]y(3) = [-ck * 3+2^{-c}]^{-\frac{1}{c}}[/tex]
[tex]16 = [-0.01 * 3 * k + 2^{-0.01}]^{\frac{-1}{0.01}}[/tex]
[tex]16 = [-0.03 * k + 2^{-0.01}]^{-100}[/tex]
[tex]16 = [-0.03 k + 0.9931]^{-100}[/tex]
Take -1/100th root of both sides
[tex]16^{-1/100} = -0.03k + 0.9931[/tex]
[tex]0.9727 = -0.03k + 0.9931[/tex]
[tex]0.03k= - 0.9727 + 0.9931[/tex]
[tex]0.03k= 0.0204[/tex]
[tex]k= \frac{0.0204}{0.03}[/tex]
[tex]k= 0.68[/tex]
Recall that:
[tex]-\frac{y^{-c}}{c} = kt+C[/tex]
This implies that:
[tex]\frac{y_0^{-c}}{c} = kT[/tex]
Make T the subject
[tex]T = \frac{y_0^{-c}}{kc}[/tex]
Substitute: [tex]k= 0.68[/tex], [tex]c = 0.01[/tex] and [tex]y_0 = 2[/tex]
[tex]T = \frac{2^{-0.01}}{0.68 * 0.01}[/tex]
[tex]T = \frac{2^{-0.01}}{0.0068}[/tex]
[tex]T = \frac{0.9931}{0.0068}[/tex]
[tex]T = 146.04[/tex]
The doomsday is 146 days
What is the minimum value of h(x)?
h(x) = (x - 5)^2 + 6
Answer:
see in pdf the solution is there.
Step-by-step explanation:
Find the circumference of the circle.
Answer:
the 3rd one 72.22 is the answer
Answer:
the formula for it is 2*3.14*r
so to get the radius you divide the diameter by two, so 23 divided by 2 is 11.50
so then we do 2*3.14*11.50= 77.22
there u go!
Step-by-step explanation:
un comerciante vende un artículo en $196 y obtiene como telera con tanto porciento igual al precio del costo del artículo Hallar el costo del artículo
Answer:
$196 es el precio del articulo
PLS HELP AND ANSWER QUICK PLZ
Answer:
X = 90° , Y = 45°, Z = 45°
Step-by-step explanation:
The length of a rectangle is x feet more than its width. The area of the rectangle is 5x + 25. What is the width of the rectangle?
Answer:
w = [tex]l + \frac{25 - l^{2}}{l - 5}[/tex]
(Anyone can correct me if I'm wrong)
Step-by-step explanation:
Before we start the solving, we can make the following statements:
Area = l x w
Area = 5x + 25
therefore,
l x w = 5x + 25
Since the question states that the length is x more than the width, so we can make the following statement:
w = l + x
With this, we can substitute it to the first statement we made, l x w = 5x + 25,
l x (l + x) = 5x + 25
[tex]l^{2}[/tex] + lx = 5x + 25
lx - 5x = 25 - [tex]l^{2}[/tex]
x(l - 5) = 25 - [tex]l^{2}[/tex]
x = [tex]\frac{25 - l^{2}}{l - 5}[/tex]
From this, we can find w by substituting it in the statement we made earlier, w = l + x,
w = [tex]l + \frac{25 - l^{2}}{l - 5}[/tex]
Find X please help me with test corrections due midnight tonight!
If HBN is congruent to LYR.
Answer:
the answer is
x=22..........
There are 20 pieces of fruit in a basket and 12 of them are oranges. What percentage of the pieces of fruit in the basket are oranges? Show your work in the box and circle your answer
Answer:60 percent
Step-by-step explanation: You have fraction the two numbers which will be 12/20 them you times it by 100 which equals 60 oranges.
1) Find the missing angle.
31°
949
? + 31° + 94° = 180°
? + 125° = 180°
? = 180° - 125°
? = 55°
Answer: 52°
Step-by-step explanation:
Angles in a triangle always add up to 180°.
So to work out what the missing angle is, you would have to add 34 and 94 together.
34+94=128
Then you would have to take 128 away from 180.
180-128=52°
Hope this helps :)
The following figure is made of a square and a rectangle.
4 cm
4 cm
7
10 cm
What is the perimeter of the figure?
cm
can someone help having trouble solving this question
Answer:
if you pit the shape in a straight line it would be 180 degrees now take 180 take 130 and 100 and subtract those add that to the other 30 then take 180 divided by 60
Answer:
x = 50°
Step-by-step explanation:
sum of exterior angles is always equal to 360°
so, we can add all the given numbers and set them equal to 360° to find x:
130° + 30° + 100° + x° + x° = 360°
260° + 2x = 360°
2x = 100°
x = 50°
please OMG I DONT UNDERSTAND
Answer:
ANSWER
Step-by-step explanation:
ANSWER THIS PLZZ I WILL GIVE TOP COMMENT :)!!!!!
Answer:
D, -42 multiply 6 on both sides
D. because when it is multiplied, the inequality is no longer true.
A roofing contractor buys 30 bundles of shingles and 4
rolls of roofing paper for $1040.
In a second purchase (at the same prices), the
contractor buys 12 bundles of shingles and 16 rolls of
roofing paper for $2000.
Create and solve a system of equations in order to
determine how much each bundle of shingles (x) and
roll of roofing paper (y) would cost
Answer:
Cost of one bundle of shingles is $20 and cost of one roll of roofing paper is $110.
Step-by-step explanation:
Let the cost of each bundle of shingles = x
And cost of the roofing paper = y
Contractor buys 30 bundles of shingles and 4 rolls of roofing paper for $1040.
30x + 4y = 1040
15x + 2y = 520 -----(1)
In a second purchase contractor buys 12 bundles of shingles and 16 rolls of roofing paper for $2000
12x + 16y = 2000
3x + 4y = 500 --- (2)
Equation (1) multiplied by 2 then subtracted from equation (2)
(3x + 4y) - 2(15x + 2y) = 500 - 1040
(3x - 30x) + (4y - 4y) = -540
-27x = -540
x = 20
From equation (1)
15(20) + 2y = 520
300 + 2y = 520
2y = 220
y = 110
Therefore, cost of one bundle of shingles is $20 and cost of one roll of roofing paper is $110.
What does 3 to the power of 2 minus 4 times 2 plus 6
Answer:
7 is the answer
Step-by-step explanation:
Answer:
This equals 7
Step-by-step explanation:
I used a calculator
Can I have brainliest pls
Divide round your answer to the nearest whole number 20,967.84÷7
find the product (ab-3)^2
Answer:
a^2b^2 -6ab + 9
Step-by-step explanation:
Which expression is equivalent to sqrt -108 - sqrt -3?
A) 5 sqrt 3i
B) 6 sqrt 3i
C) 7 sqrt 3i
D) 8 sqrt 3i
there are 144 microscopes in boxes at a school. each box has 24 microscopes which equation could be used to find b, the number of boxes of microscopes at this school
A. 24+144= b
B. 144-b= 24
C. B divided by 24= 144
D. 24 x b= 144
what is the slope of the line passing through the points (4,7) and (-2,10)?
Answer:
-1/2
Step-by-step explanation:
Answer:
the answer is the slope is -1/2
if f(x)=5x-7,what isf(3)?
Answer:
Explanation:
f ( − 3 ) basically means substitute − 3 for x in the function − 5 x
f
(
−
3
)
=
−
5
(
−
3
)
−
7
f
(
−
3
)
=
15
−
7
f
(
−
3
)
=8
Step-by-step explanation:
Helps, is it 64 111 or 90?
Answer:
111
Step-by-step explanation:
The logarithm of a number to the base V2 is k. What is its logarithm to the base 2v2 ?
Answer:
[tex]log_{2\sqrt 2} X = \frac{1}{3}k[/tex]
Step-by-step explanation:
Given
Let the number be X
From the first statement, we have:
[tex]log_{\sqrt 2} X = k[/tex]
Required
Find [tex]log_{2\sqrt 2} X[/tex]
[tex]log_{\sqrt 2} X = k[/tex]
using the following law of logarithm
[tex]log_ab = n, b=a^n[/tex]
So:
[tex]log_{\sqrt 2} X = k[/tex]
[tex]X = \sqrt{2}^k[/tex]
Substitute: [tex]X = \sqrt{2}^k[/tex] in [tex]log_{2\sqrt 2} X[/tex]
[tex]log_{2\sqrt 2} X = log_{2\sqrt 2} ( \sqrt{2}^k)[/tex]
[tex]log_{2\sqrt 2} X = klog_{2\sqrt 2} \sqrt{2}[/tex]
Apply the following law:
[tex]log_ab = \frac{log\ b}{log\ a}[/tex]
[tex]log_{2\sqrt 2} X = k\frac{log\ \sqrt 2}{log\ {2\sqrt 2}}[/tex]
Express the square roots as power
[tex]log_{2\sqrt 2} X = k\frac{log\ 2^\frac{1}{2}}{log\ {2 * 2^\frac{1}{2}}}[/tex]
[tex]log_{2\sqrt 2} X = k\frac{log\ 2^\frac{1}{2}}{log\ {2^\frac{3}{2}}}[/tex]
using the following law of logarithm
[tex]log_ab = n, b=a^n[/tex]
[tex]log_{2\sqrt 2} X = k\frac{\frac{1}{2}log\ 2}{\frac{3}{2}log\ 2}}[/tex]
[tex]log_{2\sqrt 2} X = k\frac{\frac{1}{2}}{\frac{3}{2}}}[/tex]
Rewrite as:
[tex]log_{2\sqrt 2} X = k * \frac{1}{2} \div\frac{3}{2}[/tex]
[tex]log_{2\sqrt 2} X = k * \frac{1}{2} *\frac{2}{3}[/tex]
[tex]log_{2\sqrt 2} X = k * \frac{1}{1} *\frac{1}{3}[/tex]
[tex]log_{2\sqrt 2} X = \frac{1}{3}k[/tex]
Use similar triangles to solve for the missing lengths below.
If you know how to work this out please help:)
Answer:
x = 14
y = 18
Step-by-step explanation:
By the property of similar triangles,
If two triangles are similar their corresponding sides will be proportional.
[tex]\frac{AB}{EF}= \frac{AC}{GE}[/tex]
[tex]\frac{5}{10}=\frac{7}{x}[/tex]
x = [tex]\frac{70}{5}[/tex]
x = 14
Similarly, [tex]\frac{AB}{EF}= \frac{CB}{GF}[/tex]
[tex]\frac{5}{10}=\frac{9}{y}[/tex]
y = [tex]\frac{90}{5}[/tex]
y = 18
Simplify the following expression completely, where x 20.
x5xy* + 405x’y* - 180x’y4
O xy2 5x + xy? V405x – xy2/80x
0 6xyV5x
-3xy 5x + xy? J405x
O 6xy ſ5x}
Answer:
Option B is your answer
Step-by-step explanation:
hope it helps
have a great day!!
Answer:
A.) -80X^8 + 40x^7 -5x^6 -3x^2
Its OPTION A
Step-by-step explanation:
The radius of a circle is 3.9 in. Find the circumference to the nearest tenth.
Answer:
24.5
Step-by-step explanation:
Which one was the answer A,B,C or D?
Answer:
A
Step-by-step explanation:
If one pair of supplementary angles is a right angle, the other angle must also be a right angle true or false?
Answer: True
Step-by-step explanation:
A supplementary angle refers to the angles that has a sum of 180° when they're added together.
We should note that a right angle equals to 90°, therefore the other angle in the supplementary angle will be:
= 180° - 90°
= 90°
Since a right angle equals 90°, then the other angle must be a right angle.
Therefore, the answer is TRUE.
Find the area of the shape shown below.
Answer: 4, 800
Step-by-step explanation:
I need help
Can you help me please!!!
Answer:
Step-by-step explanation:
The triangles are similar.
x/(x+4) = 7.2/12
x/(x+4) = 0.6
x = 0.6(x+4)
0.4x + 2.4
x = 6