A dog groomer charges her clients by the weight of the dog. The following piecewise function represents the total charge, f(x)

, for a dog weighing x pounds.

f(x)=⎧⎩⎨⎪⎪2.5x if 0≤x≤203.5x if 20 <x≤50 5x if x>50


What would be the last point graphed on the first piece of the function, f(x)=2.5x
?
(___,___)

11 answers

The first piece of the piecewise function is \( f(x) = 2.5x \) and is defined for the range \( 0 \leq x \leq 20 \).

To determine the last point graphed for this piece, we need to evaluate the function at the upper limit of its domain, which is \( x = 20 \):

\[ f(20) = 2.5 \times 20 = 50 \]

Thus, the last point graphed on the first piece of the function would be:

\[ (20, 50) \]

So, the answer is \((20, 50)\).

x f(x)
0 32,000
1 29,440
2 27,048.80
3 ?
Sydney bought a new car for $32,000.00. If the car depreciates in value by 8% each year, the situation can be modeled by the equation f(x)=32,000(0.92)x
. Complete the table to find the value of the car to the nearest cent after three years.(1 point)
The value of the car after three years is $(___)

To find the value of the car after three years using the depreciation model \( f(x) = 32,000(0.92)^x \), we need to calculate \( f(3) \).

Substituting \( x = 3 \):

\[ f(3) = 32,000(0.92)^3 \]

First, calculate \( (0.92)^3 \):

\[ (0.92)^3 = 0.92 \times 0.92 \times 0.92 \approx 0.778688 \]

Now, calculate \( f(3) \):

\[ f(3) = 32,000 \times 0.778688 \approx 24,964.00 \]

Thus, the value of the car after three years is approximately $24,964.00.

So the answer is:

$(24,964.00)$.

Marilee is creating a garden in her yard. She needs to put up a fence to keep the animals out of it. She has 40 yards of fencing she can erect. This situation is modeled using the equation A=−w^2+20w
, where A
is the area of the fence and w is the width of the fence. Using the equation, what is domain when the maximum range is achieved?(1 point)
Responses

10 square yards
10 square yards

100 yards
100 yards

5 yards
5 yards

10 yards

To determine the domain, we need to analyze the situation specified in the problem.

In this case, Marilee can build a rectangular enclosure using the fencing materials, with the perimeter given by \( P = 2l + 2w \), where \( l \) is the length and \( w \) is the width. Given that she has 40 yards of fencing, we can write the equation for the perimeter as:

\[ 2l + 2w = 40 \implies l + w = 20 \implies l = 20 - w \]

The area \( A \) of the rectangle is given by:

\[ A = l \cdot w = (20 - w) \cdot w = 20w - w^2 \]

This simplifies to the quadratic equation provided in the problem:

\[ A = -w^2 + 20w \]

To find the domain of this function, we need to consider the physical constraints on the width \( w \):

  1. The width \( w \) must be non-negative: \( w \geq 0 \)
  2. The total width and length must not exceed 20 yards, as \( w + l = 20 \): \( w \leq 20 \)

Combining these two constraints, the domain for \( w \) is:

\[ 0 \leq w \leq 20 \]

Now, you are asking about the maximum range when the maximum area is achieved. The maximum area occurs at the vertex of the quadratic equation. The \( w \)-coordinate of the vertex can be found using the formula \( w = -\frac{b}{2a} \), where \( A = aw^2 + bw + c \).

In our case, \( a = -1 \) and \( b = 20 \):

\[ w = -\frac{20}{2 \cdot -1} = 10 \]

At \( w = 10 \), we can find the corresponding area:

\[ A(10) = -10^2 + 20 \cdot 10 = -100 + 200 = 100 \text{ square yards} \]

The maximum area (range) of the garden is 100 square yards when the width is 10 yards.

Therefore, the domain we're discussing refers specifically to the width, which has a maximum of 20 yards, but the answer to your question about the maximum range achieved is correlated to:

10 yards (the width at which the maximum area is achieved).

A volleyball is served from a height of 6 feet with an initial velocity of 33 feet per second. The situation is modeled using the function h=−6t^2+33t+6
, where h is the height in feet and t is time in seconds. Which of the following uses the function to correctly identify the corresponding y-values to the given x-values of 0, 1, 2, 3, and 4?(1 point)
Responses

(0,6)
, (1,33)
, (2,48)
, (3,51)
and (4,42)
left parenthesis 0 comma 6 right parenthesis , left parenthesis 1 comma 33 right parenthesis , left parenthesis 2 comma 48 right parenthesis , left parenthesis 3 comma 51 right parenthesis and left parenthesis 4 comma 42 right parenthesis

(0,0)
, (1,27)
, (2,42)
, (3,45)
, and (4,36)
left parenthesis 0 comma 0 right parenthesis , left parenthesis 1 comma 27 right parenthesis , left parenthesis 2 comma 42 right parenthesis , left parenthesis 3 comma 45 right parenthesis , and left parenthesis 4 comma 36 right parenthesis

(0,6)
, (1,21)
, (2,48)
, (3,69)
, and (4,90)
left parenthesis 0 comma 6 right parenthesis , left parenthesis 1 comma 21 right parenthesis , left parenthesis 2 comma 48 right parenthesis , left parenthesis 3 comma 69 right parenthesis , and left parenthesis 4 comma 90 right parenthesis

(6,0)
, (33,1)
, (48,2)
, (51,3)
, and (42,4)

To determine the correct pairs of \( (t, h) \) using the function \( h = -6t^2 + 33t + 6 \) for \( t = 0, 1, 2, 3, 4 \), we need to evaluate the function at each specific \( t \).

  1. For \( t = 0 \): \[ h(0) = -6(0)^2 + 33(0) + 6 = 6 \]

  2. For \( t = 1 \): \[ h(1) = -6(1)^2 + 33(1) + 6 = -6 + 33 + 6 = 33 \]

  3. For \( t = 2 \): \[ h(2) = -6(2)^2 + 33(2) + 6 = -24 + 66 + 6 = 48 \]

  4. For \( t = 3 \): \[ h(3) = -6(3)^2 + 33(3) + 6 = -54 + 99 + 6 = 51 \]

  5. For \( t = 4 \): \[ h(4) = -6(4)^2 + 33(4) + 6 = -96 + 132 + 6 = 42 \]

Now we can summarize our results:

  • For \( t = 0 \), \( h(0) = 6 \) → \( (0, 6) \)
  • For \( t = 1 \), \( h(1) = 33 \) → \( (1, 33) \)
  • For \( t = 2 \), \( h(2) = 48 \) → \( (2, 48) \)
  • For \( t = 3 \), \( h(3) = 51 \) → \( (3, 51) \)
  • For \( t = 4 \), \( h(4) = 42 \) → \( (4, 42) \)

Thus, the correct corresponding pairs of \( (t, h) \) values are:

\[ (0,6), (1,33), (2,48), (3,51), \text{ and } (4,42) \]

The correct response from the options provided is:

(0,6), (1,33), (2,48), (3,51), and (4,42).

Nora is creating a dog run in her backyard for her dog, Max. She has enough materials to create a run with a perimeter of 120 feet. This is represented by the function A=−w^2+60w
, where A
is the area of the run and w is the width. Which of the following best analyzes the meaning of the x-intercept?(1 point)
Responses

The dog run must have a width between 0 and 900 feet.
The dog run must have a width between 0 and 900 feet.

The dog run must have a width between 0 and 60 feet.
The dog run must have a width between 0 and 60 feet.

The dog run must have a width between 0 and 30 feet.
The dog run must have a width between 0 and 30 feet.

The dog run must have a width between 0 and 120 feet.

To analyze the meaning of the x-intercepts of the function \( A = -w^2 + 60w \), we first need to find the x-intercepts. The x-intercepts occur when the area \( A \) is equal to zero:

\[ 0 = -w^2 + 60w \]

Factoring this equation gives:

\[ 0 = w(-w + 60) \]

Setting each factor to zero, we find the x-intercepts:

  1. \( w = 0 \)
  2. \( -w + 60 = 0 \implies w = 60 \)

The x-intercepts at \( w = 0 \) and \( w = 60 \) indicate the valid widths of the dog run:

  • \( w = 0 \) means there is no width (no dog run).
  • \( w = 60 \) represents the maximum width before the area drops to zero.

The area function \( A = -w^2 + 60w \) is a downward-opening parabola with its maximum point occurring at \( w = 30 \) (the vertex). The area is positive between the intercepts (when \( 0 < w < 60 \)).

Based on this analysis, the correct interpretation of the x-intercepts is:

The dog run must have a width between 0 and 60 feet.

So the response is:

The dog run must have a width between 0 and 60 feet.

the graph shows 0 to 7 on the x-axis(ours) ,with the y-axis(amount in dollars) being 0, 5, 10, 15, 20, 25 , 30 ,35 , 40 the line on the graph starts from 5 on the y-axis going upwards towards 40 in between 3 and 4 on the x axis
Using this graph of a linear equation as an example, create a real-world situation that the graph could model. In 1 sentence explain what the graph is modeling.

Situation: A local charity organizes a fundraising event where they sell tickets at a price of $5 each, and for every additional ticket sold (up to 7 tickets), the total amount raised increases linearly, with the goal of reaching $40 in donations.

Explanation: The graph models the total amount of money raised (in dollars) as a function of the number of tickets sold, showing how the total donation increases with each ticket sold.