Will give brainliest if correct what is the discriminant of the quadratic equation: (multiple choice)

Complete question is;

A 10 cm thick grindstone is initially 200 cm in diameter, and it is wearing away at a rate of 50 cm/hr. At what rate is its diameter decreasing?

Answer:

Diameter is decreasing at the rate of 5/(2πr) cm/hr

Step-by-step explanation:

We are told the stone is wearing away at a rate of 50 cm/hr. This means the volume is decreasing. Thus;

dV/dt = -50 cm/hr

Now, a grindstone is in the shape of a cylinder. Thus, volume of grindstone is;

V = πr²h

dV/dr = 2πrh

Now,to find the rate at which the diameter is decreasing, we'll write;

dr/dt = (dV/dt)/(dV/dr)

dr/dt = -50/(2πrh)

We are given;

Diameter = 200 cm

Radius; r = 200/2 = 100 cm

Thickness; h = 10 cm

Thus;

dr/dt = -50/(2π × r × 10)

dr/dt = -5/(2πr) cm/hr

The rate at which grindstone diameter decreases is [tex]-5/2\pi r \;{\rm cm/hr}[/tex] and this can be determined by using the given data.

Given :

A 10 cm thick grindstone is initially 200 cm in diameter and it is wearing away at a rate of 50 [tex]\rm cm^3/hr[/tex].

The following steps can be used in order to determine the rate at which grindstone diameter decreases:

Step 1 - According to the given data, the rate at which grindstone volume decreases is:

[tex]\dfrac{dV}{dt} = 50\;{\rm cm^3/hr}[/tex]        --- (1)

Step 2 -  The formula of the volume of the cylinder (grindstone) is given below:

[tex]V = \pi r^2 h[/tex]

Step 3 - Differentiate the above expression with respect to 'r'.

[tex]\dfrac{dV}{dr} = 2\pi r h[/tex]          --- (2)

Step 4 - So, using the expression (1) and (2) the rate at which grindstone diameter decreases is:

[tex]\dfrac{dr}{dt}=\dfrac{\frac{dV}{dt}}{\frac{dV}{dr}}[/tex]

[tex]\dfrac{dr}{dt}=\dfrac{-50}{2\pi r \times 10}\\[/tex]

[tex]\dfrac{dr}{dt} = -\dfrac{5}{2\pi r }\; {\rm cm/hr}[/tex]

So, the rate at which grindstone diameter decreases is [tex]-5/2\pi r \;{\rm cm/hr}[/tex].

For more information, refer to the link given below:

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Answer:

sometimes true

Step-by-step explanation:

Answer:

Step-by-step explanation:

The Order of Operations is very important when simplifying expressions and equations. The Order of Operations is a standard that defines the order in which you should simplify different operations such as addition, subtraction, multiplication and division.

This standard is critical to simplifying and solving different algebra problems. Without it, two different people may interpret an equation or expression in different ways and come up with different answers. The Order of Operations is shown below.

Parentheses and Brackets -- Simplify the inside of parentheses and brackets before you deal with the exponent (if any) of the set of parentheses or remove the parentheses.

Exponents -- Simplify the exponent of a number or of a set of parentheses before you multiply, divide, add, or subtract it.

Multiplication and Division -- Simplify multiplication and division in the order that they appear from left to right.

Addition and Subtraction -- Simplify addition and subtraction in the order that they appear from left to right.

Before we begin simplifying problems using the Order of Operations, let's examine how failure to use the Order of Operations can result in a wrong answer to a problem.

Without the Order of Operations one might decide to simplify the problem working left to right. He or she would add two and five to get seven, then multiply seven by x to get a final answer of 7x. Another person might decide to make the problem a little easier by multiplying first. He or she would have first multiplied 5 by x to get 5x and then found that you can't add 2 and 5x so his or her final answer would be 2 + 5x. Without a standard like the Order of Operations, a problem can be interpreted many different ways

We cannot combine the variable terms before using the distributive property when solving the equation as it will results in wrong answer.

What is distributive property of multiplication over addition ?

If we multiply a number by the sum of more than two, we use the distributive property of multiplication over addition.

Here the expression given is :

7(x+5)-x=42

The Order of Operations is very important when simplifying expressions and equations. The Order of Operations is a standard that defines the order in which you should simplify different operations such as addition, subtraction, multiplication and division.

Parentheses and Brackets -- Simplify the inside of parentheses and brackets before you deal with the exponent (if any) of the set of parentheses or remove the parentheses.

Exponents -- Simplify the exponent of a number or of a set of parentheses before you multiply, divide, add, or subtract it.

Multiplication and Division -- Simplify multiplication and division in the order that they appear from left to right.

Addition and Subtraction -- Simplify addition and subtraction in the order that they appear from left to right.

Without the Order of Operations one might decide to simplify the problem working left to right. He or she would add two and five to get seven, then multiply seven by x to get a final answer of 7x. Another person might decide to make the problem a little easier by multiplying first. He or she would have first multiplied 5 by x to get 5x and then found that you can't add 2 and 5x so his or her final answer would be 2 + 5x. Without a standard like the Order of Operations, a problem can be interpreted many different ways.

Read more about property of multiplication here :

https://brainly.com/question/14391436

#SPJ2

Answer:

There's no evidence to show that the recent experience suggests a decline in spending.

Step-by-step explanation:

We are given;

Population mean; μ = $2.5

Population Standard deviation; σ = $0.9

Sample mean; x¯ = $2.1

Sample size; n = 18

Significance level; α = 0.01

Let's define the hypothesis;

Null hypothesis; H0: μ ≥ $2.5

Alternative hypothesis; Ha: μ < $2.5

z-score formula is;

z = (x¯ - μ)/(σ/√n)

z = (2.1 - 2.5)/(0.9/√18)

z = -0.4/0.2121

z = -1.886

Using the p-value from z-score calculator attached and using z = -1.886; α = 0.01; one tail; we have;

P-value = 0.2965

This is more than the significance level. Thus, we will fail to reject the null hypothesis and conclude that there is no evidence to show that the recent experience suggests a decline in spending.

We're given two pairs of congruent sides, and a pair of congruent angles. The angles are not between the two congruent sides. So we don't have enough information to know if the triangles are congruent or not. SSA is not a valid congruence theorem. This is because there are some cases where two triangles are possible leading to ambiguity.

If the marked angles were between the tickmarked sides, then we could use SAS.

Answer:  d = -9/8

Steps: 5d + ½ = d - 4

Subtract ½ from both sides: 5d + ½ - ½  = d - 4 - ½

Simplify: 5d = d - 9/2

Subtract d from both sides: 5d - d = d - 9/2 - d

Simplify: 4d = -9/2 ÷ 4

Simplify: d = -9/8

PLz mark brainliest:)

Answer:

There are four main types of transformations: translation, rotation, reflection and dilation.Translation moves the object without rotating it or changing its size. Reflection flips the object about a line of reflection. Rotation rotates a figure about a fixed point. Dilation changes the size of a figure without changing its essential shape.When you reflect a point across the x-axis, the x-coordinate remains the same,but the y-coordinate is transformed into its opposite. a negative angle of rotation turns the figure in a clockwise direction.Transformation can be done in a number of ways, including reflection, rotation, and translation. ~When you reflect a point across the x-axis, the x-coordinate remains the same,but the y-coordinate is transformed into its opposite. a negative angle of rotation turns the figure in a clockwise direction.

Step-by-step explanation:

Transformation simply means changing the size and location of shapes, lines and points in the coordinate geometry

The similarities

Translations, reflections, and rotations are all rigid transformations

This means that, they do not change the side lengths and angle measure of the shape they transform.

The differences

Translation: can only change the position of shapes without rotating or flipping the shape.

Rotation: This means that a shape is to be turned around a center at a particular degree

Reflection: This simply means that, a shape is mirrored over a line

Real-world transformation

A scenario is when the blades of a fan rotates when the fan is powered on

Examples

Reflection

Rotation

Translation

Read more about transformations at:

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Answer:

Not a Function

Step-by-step explanation:

Answer:

Step-by-step explanation:

First find the angle in the lower left.

180 - 100 = 80

3x + 2x + 80 = 360

solve for x

5x = 280

5x/5 = 280/ 5

x = 56

Plug this in to make sure the equation is true

3(56) + 2(56) + 80 = 360

168 + 112 + 80 = 360

360 =360

Therefore x = 56

Answer:

Step-by-step explanation:

75

Answer:

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

Step-by-step explanation:

Recall that the the equation of a line in slope-intercept form is given as [tex] y = mx + b [/tex].

m = the slope of the line

b = the y-intercept. This is the point at which the line intercepts the y-axis.

We are given:

slope (m) = ⅖

y-intercept (b) = -6

All you need to do to get an equation of the line is to simply substitute m = ⅔ and b = -6 into [tex] y = mx + b [/tex].

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

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

The equation for the line is .[tex] y = \frac{2}{3}x - 6 [/tex]

Answer:

33.

Step-by-step explanation:

I assume that the 2 triangles are similar.

x/77 = 24/56

56x = 77*24

x = (77*24(/56

x = 33.

Answer:

4.05 is greater than 0.45

Answer:

Answer is 12x+4. Hope that helped.

Answer:

1

Step-by-step explanation:

3/4 + 1/4 since they both have a 4 as the denominator you only have to add the top since they made it easy. and since that would be 4/4 your answer would be 1 whole.

im not sure just yet

Answer:

134 is the answer

Answer: 134

Step-by-step explanation:

54+ (48+72) x 2/3

54+120x2/3=134

Answer:x= -3/8

Step-by-step explanation:

Answer:

-3/8

Step-by-step explanation:

4(3-2x)=15

-3/8

Answer:

-4w+4

Step-by-step explanation:

Answer:

-4w+4 Is te correct answer

1) The domain is [0,300]. The range is [0,250]

2) The slope for the initial climb is 3.57. The equation of the line is

3) The rate of change of the second hill is -1.4

4) The rate of change of the third hill is -2.1

5) The blue hill is steeper

6) It is not a function

Step-by-step explanation:

1)

The domain of a function is the set of values of x (the input) for which the function itself is defined.

Instead, the range of a function is the set of values of y (the output) that the function can take.

To find the domain, we have to look at the x-axis and see for which values of x the function is defined. By looking at the graph, we see that the function is defined between

x = 0 and x = 300

So, the domain is [0,300].

To find the range, we have to look at the y-axis and see for which values of y the function has an output. By looking at the graph, we see that the function has values of y between

y = 0 and x = 250

So, the range is [0,250].

2)

The slope of a function in a certain range is given by

where

is the change in the y-coordinate

is the change in the x-coordinate

For the initial climb (pink line), we have:

Therefore, the slope in this part is

We can now write the equation of the line in the form

y = mx + b

where b is the y-intercept: since it is zero, the line has simply the form

3)

Again, to calculate the slope of the hill, we use:

where

is the change in the y-coordinate

is the change in the x-coordinate

For the green hill, we have:

So the rate of change is

4)

As before, the rate of change of the hill is

For the blue hill, we have:

So the rate of change is

5)

To know which hill is steeper, we need to compare the magnitude of their rate of change.

In fact, both hills have rate of change negative - because we are going down along the slope. Therefore, we have to consider the magnitude of their slope.

For the green hill:

For the blue hill:

We see that the blue hill has a greater slope (in magnitude): therefore, the blue hill is steeper.

6)

A function is defined as a mapping (operation between two sets of variables) in which to one value of x (the input) corresponds one and only one value of y (the output).

This means that a function cannot have multiple values of y for the same x (the input).

By looking at the graph, we see that this function does not respect this criterium: in fact, we see that certain values of x give multiple values of the output, y (for instance, at x=300 the function has two values). So, this is not a function.

Answer:

VW = 36

Step-by-step explanation:

From the question, we are given:

VW = 5x - 4, UV = 2x,

UW = 52

Hence,

UV + VW= UW

2x + 5x - 4 = 52

7x = 52 + 4

7x = 56

x = 56/7

x = 8

VW = 5x - 4,

VW = 5(8) - 4

VW = 40 - 4

VW = 36

Given :-

ΔBCD ≅ ΔGEF

Then :-

∠B <=> ∠G ( ∠B = ∠G )

∠C <=> ∠E ( ∠C = ∠E )

∠D <=> ∠F ( ∠ D = ∠F )

BC <=> GE ( BC = GE )

CD <=> EF ( CD = EF )

BD <=> GF ( BD = GF )

Using this let us find CD .

CD = EF

Which means :-

[tex] 3x + 8 = 4x + 6[/tex]

[tex]8 = 4x + 6 - 3x[/tex]

[tex]8 = 1x + 6[/tex]

[tex]1x + 6= 8[/tex]

[tex]1x = 8 - 6[/tex]

[tex]1x = 2[/tex]

[tex]x = 2[/tex]

Then :-

EF =

[tex]EF = 4x + 6 \\ = 4 \times 2 + 6 \\ = 8 + 6 \\ = 14[/tex]

CD =

[tex]CD = 3x + 8 \\ = 3 \times 2 + 8 \\ = 6 + 8 \\ = 14[/tex]

△BCD≅△GEF

The measure of CD is 14

Given :

Two triangles are congruent

△BCD≅△GEF

When triangles are congruent then the sides are equal

[tex]BC=GE\\CD=EF\\DB=FG\\[/tex]

Given that CD=3x+8 and EF=4x+6

[tex]CD=EF\\3x+8=4x+6\\3x+8-3x=4x-3x+6\\8=x+6\\8-6=x+6-6\\x=2[/tex]

The value of x=2

Now we find measure of CD

[tex]CD=3x+8\\CD=3(2)+8\\CD=14[/tex]

The measure of CD is 14

Learn more :  brainly.com/question/18373823

Answer:

v=2(x - 1)(x-6)=2(x²-6x-x+6)=12x²-12x-2x+12

v = 12x²-14x+12  standard form

Step-by-step explanation:

Answer:

-44ax^2-198x^2+66a+297

Step-by-step explanation:

there

9514 1404 393

Answer:

  -2

Step-by-step explanation:

The average rate of change on the interval [3, 9] is ...

  (f(9) -f(3))/(9 -3) = (41 -53)/(9 -3) = -12/6 = -2

Answer:

y-7/ 12y+3

Step-by-step explanation:

Answer:

answer is 9 in th by form of the good answer is the to k=9.0 10á gd gd

Answer:

5/9

Step-by-step explanation:

2/3 • 5/2 • 2/3

1/3 • 2/5 • 2/3

multiply 1/3 for 5/2

5

-----------

3 • 2

multiply 3 for 2

5/6 • 2/3

anular el factor común 2

5/3 • 1/3

multiply 5/3 for 1/3

5

------------

3 • 3

multiply 3 for 3

5/9

the result

5/9

form decimal

0.5

Answer:

-3 = -12

Step-by-step explanation:

Have a great day

I hope that is the answer you are looking for :)