Plz help! Urgent!

1) To the nearest tenth, what is the population density of bacteria at the end of the third hour in petri dish A?

2) To the nearest tenth, which petri dish has the greatest population density of bacteria at the end of the third hour and by how much?

Answer: 12 students

Step-by-step explanation:

1/6 of 900 is 30 kids. and 2/5 of the 30 kids is 12

Answer:

a) The vertex of the graph is [tex](h,k) = (0, 31)[/tex], b) [tex]a = -16[/tex], c) The equation of the parabola is [tex]f(t) = -16\cdot t^{2}+31[/tex].

Step-by-step explanation:

a) The tennis ball experiments a free fall, that is, an uniform accelerated motion due to gravity and in which effects from Earth's rotation and air viscocity are negligible. The height of the ball in time is represented by a second order polynomial. Hence, the vertex of the parabola is the initial point highlighted in graph.

The vertex of the graph is [tex](h,k) = (0, 31)[/tex].

b) If we know that [tex](h,k) = (0, 31)[/tex], [tex]f(t) = a\cdot (t-h)^{2} + k[/tex] and [tex](t,f(t)) = (1,15)[/tex], then the value of [tex]a[/tex] is:

[tex]f(t) = a\cdot (t-h)^{2} + k[/tex]

[tex]15 = a\cdot (1-0)^{2}+31[/tex]

[tex]15 = a\cdot 1 + 31[/tex]

[tex]a = 15-31[/tex]

[tex]a = -16[/tex]

c) The equation of the parabola is [tex]f(t) = -16\cdot t^{2}+31[/tex].

Answer:

Step-by-step explanation:

2 units squared.

Explanation:

You can go about this in two ways: Algebra and Integrals.

Algebra

y = 2x-6 is linear, thus if we take the value over the x interval [2,4] we can use geometry to calculate the area.

graph{2x-6 [-2.27, 7.73, -2.18, 2.82]}

You can see two triangles in the graph (you could also find this algebraically). Thus, you can calculate the area.

=

2

⋅

(

1

2

⋅

b

⋅

h

)

=

2

⋅

(

1

2

⋅

1

⋅

2

)

=

2

square units

Integrals

An integral gives the area under the curve. Remember though that if a function goes below the X axis, the integral is negative Thus you have to do two separate integrals based on the X intercept.

finding the X intercept (that is where y = 0)

2

x

−

6

=

0

x

=

3

when

y

=

0

When

x

<

3

, then y is negative. Thus, we have to find the negative integral from 2 to 3 and the positive integral from 3 to 4

=

−

∫

3

2

2

x

−

6

d

x

+

∫

4

3

2

x

−

6

d

x

=

−

[

x

2

−

6

x

]

3

2

+

[

x

2

−

6

x

]

4

3

=

−

[

9

−

18

−

4

+

12

]

+

[

16

−

24

−

9

+

18

]

=

−

[

−

1

]

+

[

1

]

=

2

units squared. And Tada, that is the same as the other answer!

Using integrals, it is found that the area of the function is of 6 squared units.

The area of a function f(x) over an interval [a,b] is given by:

[tex]A = \int_{a}^{b} f(x) dx[/tex]

In this problem:

[tex]A = \int_{-4}^{2} 2x + 3 dx[/tex]

[tex]A = x^2 + 3x|_{x = -4}^{x = 2}[/tex]

[tex]A = 2^2 + 3(2) - [(-4)^2 + 3(-4)][/tex]

[tex]A = 4 + 6 - 4[/tex]

[tex]A = 6[/tex]

The area is of 6 squared units.

A similar problem is given at https://brainly.com/question/20733870

Answer:

The answer is "294.2075".

Step-by-step explanation:

Given:

[tex]\hat{p} = 0.5 \\\\1 - \hat{p} = 1 - 0.5 = 0.5\\\\E = 4\% = 0.04\\\\[/tex]

At [tex]83\%[/tex] confidence level the z is ,

[tex]\alpha = 1 - 83\% = 1 - 0.83 = 0.17\\\\\frac{\alpha}{2} = \frac{0.17}{2} = 0.085\\\\Z_{\frac{\alpha}{2}} = Z_{0.085} = 1.3722\\\\n = (\frac{Z_{\frac{\alpha}{2}}}{E})^2 \times \hat{p} \times (1 - \hat{p})\\\\[/tex]

   [tex]= (\frac{1.3722}{0.04})^2 \times 0.5 \times 0.5\\\\= (34.305)^2 \times 0.5 \times 0.5\\\\= 1,176.83 \times 0.5 \times 0.5\\\\= 1,176.83 \times 0.25\\\\=294.2075[/tex]

Answer:

The initial height of the arrow is 1.5 feet above the ground.

Step-by-step explanation:

Let be the height of the arrow be represented by the function [tex]h(t) = -16\cdot t^{2}+128\cdot t + 1.5[/tex], where [tex]h(t)[/tex] is the current height of the arrow, measured in feet, and [tex]t[/tex], is the time, measured in seconds.

Mathematically speaking, the initial height is the value of [tex]h[/tex] evaluated at [tex]t = 0\,s[/tex]. That is:

[tex]h(0) = -16\cdot (0)^{2}+128\cdot (0) + 1.5[/tex]

[tex]h(0) = 1.5\,ft[/tex]

The initial height of the arrow is 1.5 feet above the ground.

[tex]x = \frac{7 \sqrt{3} }{2} \\ [/tex]

.

[tex] \frac{7}{x} = \frac{2}{ \sqrt{3} } \\ [/tex]

[tex]7 \times \sqrt{3} = 2 \times x[/tex]

[tex]7 \sqrt{3} = 2x[/tex]

[tex] \frac{7 \sqrt{3} }{2} = x \\ [/tex]

[tex]x = \frac{7 \sqrt{3} }{2} \\ [/tex]

.

.

#LearnWithBrainly

Answer:

Step-by-step explanation:

Answer:

18/35....

....

YESTERDAY

Answer: 60 ounces of flour

Step-by-step explanation:

8•7.5=60

Answer:

1.25

Step-by-step explanation:

5/4=1.25

Answer:

$4.30 for 2 glass panes

Step-by-step explanation:

15.05/7=2.15

$2.15 per glass pane

2.15(2)=4.30

$4.30 for 2 glass panes

Answer:

65850

Step-by-step explanation:

Answer:

65,850

Step-by-step explanation:

5 laptops costs 163,750(5x32750). Total costs of 229,600-laptops 163,750=costs of desktop 65850.

Answer:

Volume of cone = 72 ft³

Step-by-step explanation:

diameter = 6ft

radius = 3ft

height = 8ft

Volume of a cone = [tex]\frac{\pi r^2h}{3}[/tex]

V = (3 × 3 × 3 × 8)/3

V = 72 ft³

Answer:

V ≈  72 ft³

Step-by-step explanation:

Given that volume (V) is calculated using

V = [tex]\frac{\pi r^2h}{3}[/tex] ( r is the base radius and h the height )

Here diameter d = 6 then r = 6 ÷ 2 = 3 and h = 8 , then

V = [tex]\frac{3(3^2)(8)}{3}[/tex] ( cancel 3 on numerator/ denominator )

   = 9 × 8

   = 72 ft³

Answer:

525cmlong the length of seeds

Answer:

what do you do

Step-by-step explanation:

Answer:

1) 6x+3y=5    

Step-by-step explanation:

1) First, find the slope of the line passing through (-4, -1) and (-1, -7). Use the slope formula [tex]m = \frac{y_2-y_1}{x_2-x_1}[/tex]. Substitute the x and y values of the two points into the formula and solve:

[tex]m = \frac{(-7)-(-1)}{(-1)-(-4)} \\m = \frac{-7+1}{-1+4} \\m = \frac{-6}{3} \\m = -2[/tex]

So, the slope is -2.

2) Now, identify the slopes of the lines in the options. We already know the slope of [tex]y = -\frac{1}{2} x-7[/tex]  is [tex]-\frac{1}{2}[/tex] since it is in slope-intercept form. y = -2 must have a slope of 0 since it's horizontal, and all equations with the format of y = a number are horizontal.

To find the slope of [tex]6x + 3y = 5[/tex], isolate y to put the equations into slope-intercept form ([tex]y = mx + b[/tex] format), and whatever the coefficient of the x-term is will be the slope.

[tex]6x + 3y = 5\\3y = -6x+5\\y = -2x + \frac{5}{3}[/tex].

So, the slope of the first option is -2. It matches the slope we calculated in the first step, so that must be the answer.

Answer:

Washing Powder

Step-by-step explanation:

Cost less and cleans better.

Answer:

The washing powder I think?

Step-by-step explanation:

Answer:

A

Step-by-step explanation:

y -2 = -5/6(x -3)

y-2 = -5/6x + 15/6

y = -5/6x + 27/6

y = -5/6x + 9/2

Answer:

y = 1/2x - 4

Step-by-step explanation:

If two lines are perpendicular to each other, they have opposite slopes.

The first line is y = -2x + 8. Its slope is -2. A line perpendicular to this one will  have a slope of 1/2.

Plug this value (1/2) into your standard point-slope equation of y = mx + b.

y = 1/2x + b

To find b, we want to plug in a value that we know is on this line: in this case, it is (4, -2). Plug in the x and y values into the x and y of the standard equation.

-2 = 1/2(4) + b

To find b, multiply the slope and the input of x (4)

-2 = 2 + b

Now, subtract 2 from both sides to isolate b.

-4 = b

Plug this into your standard equation.

y = 1/2x - 4

This equation is perpendicular to your given equation (y = -2x + 8) and contains point (4, -2)

Hope this helps!

9514 1404 393

Answer:

  y = 1/2x -4

Step-by-step explanation:

We presume the given line is ...

  y = -2x +8

This is in slope-intercept form, which allows us to determine easily that the slope of this line is -2.

A perpendicular line will have a slope that is the opposite reciprocal of -2:

  m = -1/(-2) = 1/2

The y-intercept of the desired line can be found from the point (x, y) = (4, -2) using the equation ...

  b = y - mx

  b = -2 -(1/2)(4) = -4

Now, we know the slope and y-intercept of the desired perpendicular line through (4, -2), so we can write its equation as ...

  y = 1/2x -4

__

Additional comment

"Slope-intercept form" is ...

  y = mx + b . . . . . . where m is the slope and b is the y-intercept

Answer:

Step-by-step explanation:

lcm = 3150

hcf= 15

Answer:

75 meters.

Step-by-step explanation:

In this case, you are trying to find side length NO. In accordance to SOH CAH TOA, you can use a sine function to find the missing side length, since you are given the hypotenuse.

sin(49) = x / 100

x = sin(49) * 100

x = 0.7547095802 * 100

x = 75.47095802

So, the closest answer would be 75 meters.

Hope this helps!

9514 1404 393

Answer:

Step-by-step explanation:

We can rewrite the equation to standard form to see the center and semi-axis lengths.

  16x^2 -128x +y^2 +3y = -256

  16(x^2 -8x +16) +(y^2 +3y +2.25) = -256 +256 +2.25

  16(x -4)^2 +(y +1.5)^2 = 9/4 . . . . . write as squares

  (x -4)^2/(9/64) +(y +1.5)^2/(9/4) = 1 . . . . divide by 9/4

  ((x -4)/0.375)^2 +((y +1.5)/1.5)^2 = 1 . . . . put in useful form

In this form, we have ...

  ((x -h)/a)^2 +((y -k)/b)^2 = 1

where (h, k) is the center, 2a is the length of the axis in the x-direction, and 2b is the length of the axis in the y-direction. The required tangents are ...

  x = h±a

  y = k±b

For the given ellipse, the tangent lines are ...

Answer:

72°

Step-by-step explanation:

To convert from degrees to radians, multiply the degrees by [tex]\frac{\pi }{180}[/tex].

To convert from radians to degrees, multiply the radians by [tex]\frac{180}{\pi }[/tex].

Right now you're in radians, so multiply it by [tex]\frac{180}{\pi }[/tex].

[tex]\frac{12\pi }{5}* \frac{180}{\pi }[/tex]=[tex]432[/tex]°.

Now we need to find the reference angle for 432°.

If you draw 432° starting from the right and going clockwise (because it is a positive angle, if it was negative you would go counterclockwise), it will make one full rotation, which is 360°, and you will end up in the 1st quadrant, 72° past 360°.

Depending on the quadrant you land in, there might be different operations to perform. Please check the attached image.

In this case, we're in the 1st quadrant so we can leave the angle as is.

The answer is 72°.

Answer:

false

Step-by-step explanation:

Answer:

Congruent angles are equal. The answer is false

9514 1404 393

Answer:

  42.3

Step-by-step explanation:

The appropriate trig ratio is ...

  Tan = Opposite/Adjacent

  tan(78°) = x/9

  x = 9×tan(78°)

  x ≈ 42.3