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RSB [31]
3 years ago
5

A razorblade manufacturer wants to test responses to a new blade for heavy beards. What is the best sample for an experiment?

Mathematics
2 answers:
myrzilka [38]3 years ago
7 0

Answer:

A

Step-by-step explanation:

Keith_Richards [23]3 years ago
5 0
The right answer would be A random sample of men who shave andn have heavy beard because the person should like to shave because you shouldn't force them to try it. They also need to have a heavy beard because the manufacturer is creating a razor blade for men with heavy beards. Hope this helps.
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Answer:

c)

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Find the length of the missing side. Leave your answer in simplest radical form.
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4 years ago
The spread of a virus is modeled by V (t) = −t 3 + t 2 + 12t,
VashaNatasha [74]

Functions can be used to model real life scenarios

  • The reasonable domain is \mathbf{[0,\infty)}.
  • The average rate of change from t = 0 to 2 is 20 persons per week
  • The instantaneous rate of change is \mathbf{V'(t) = -3t^2 + 2t + 12}.
  • The slope of the tangent line at point (2,V(20) is 10
  • The rate of infection at the maximum point is 8.79 people per week

The function is given as:

\mathbf{V(t) = -t^3 + t^2 + 12t}

<u>(a) Sketch V(t)</u>

See attachment for the graph of \mathbf{V(t) = -t^3 + t^2 + 12t}

<u />

<u>(b) The reasonable domain</u>

t represents the number of weeks.

This means that: <em>t cannot be negative.</em>

So, the reasonable domain is: \mathbf{[0,\infty)}

<u />

<u>(c) Average rate of change from t = 0 to 2</u>

This is calculated as:

\mathbf{m = \frac{V(a) - V(b)}{a - b}}

So, we have:

\mathbf{m = \frac{V(2) - V(0)}{2 - 0}}

\mathbf{m = \frac{V(2) - V(0)}{2}}

Calculate <em>V(2) and V(0)</em>

\mathbf{V(2) = (-2)^3 + (2)^2 + 12 \times 2 = 20}

\mathbf{V(0) = (0)^3 + (0)^2 + 12 \times 0 = 0}

So, we have:

\mathbf{m = \frac{20 - 0}{2}}

\mathbf{m = \frac{20}{2}}

\mathbf{m = 10}

Hence, the average rate of change from t = 0 to 2 is 20

<u>(d) The instantaneous rate of change using limits</u>

\mathbf{V(t) = -t^3 + t^2 + 12t}

The instantaneous rate of change is calculated as:

\mathbf{V'(t) = \lim_{h \to \infty} \frac{V(t + h) - V(t)}{h}}

So, we have:

\mathbf{V(t + h) = (-(t + h))^3 + (t + h)^2 + 12(t + h)}

\mathbf{V(t + h) = (-t - h)^3 + (t + h)^2 + 12(t + h)}

Expand

\mathbf{V(t + h) = (-t)^3 +3(-t)^2(-h) +3(-t)(-h)^2 + (-h)^3 + t^2 + 2th+ h^2 + 12t + 12h}\mathbf{V(t + h) = -t^3 -3t^2h -3th^2 - h^3 + t^2 + 2th+ h^2 + 12t + 12h}

Subtract V(t) from both sides

\mathbf{V(t + h) - V(t)= -t^3 -3t^2h -3th^2 - h^3 + t^2 + 2th+ h^2 + 12t + 12h - V(t)}

Substitute \mathbf{V(t) = -t^3 + t^2 + 12t}

\mathbf{V(t + h) - V(t)= -t^3 -3t^2h -3th^2 - h^3 + t^2 + 2th+ h^2 + 12t + 12h +t^3 - t^2 - 12t}

Cancel out common terms

\mathbf{V(t + h) - V(t)= -3t^2h -3th^2 - h^3  + 2th+ h^2  + 12h}

\mathbf{V'(t) = \lim_{h \to \infty} \frac{V(t + h) - V(t)}{h}} becomes

\mathbf{V'(t) = \lim_{h \to \infty} \frac{ -3t^2h -3th^2 - h^3  + 2th+ h^2  + 12h}{h}}

\mathbf{V'(t) = \lim_{h \to \infty} -3t^2 -3th - h^2  + 2t+ h  + 12}

Limit h to 0

\mathbf{V'(t) = -3t^2 -3t\times 0 - 0^2  + 2t+ 0  + 12}

\mathbf{V'(t) = -3t^2 + 2t + 12}

<u>(e) V(2) and V'(2)</u>

Substitute 2 for t in V(t) and V'(t)

So, we have:

\mathbf{V(2) = (-2)^3 + (2)^2 + 12 \times 2 = 20}

\mathbf{V'(2) = -3 \times 2^2 + 2 \times 2 + 12 = 4}

<em>Interpretation</em>

V(2) means that, 20 people were infected after 2 weeks of the virus spread

V'(2) means that, the rate of infection of the virus after 2 weeks is 4 people per week

<u>(f) Sketch the tangent line at (2,V(2))</u>

See attachment for the tangent line

The slope of this line is:

\mathbf{m = \frac{V(2)}{2}}

\mathbf{m = \frac{20}{2}}

\mathbf{m = 10}

The slope of the tangent line is 10

<u>(g) Estimate V(2.1)</u>

The <em>value of 2.1 </em>is

\mathbf{V(2.1) = (-2.1)^3 + (2.1)^2 + 12 \times 2.1}

\mathbf{V(2.1) = 20.35}

<u />

<u>(h) The maximum number of people infected at the same time</u>

Using the graph, the maximum point on the graph is:

\mathbf{(t,V(t) = (2.361,20.745)}

This means that:

The maximum number of people infected at the same time is approximately 21.

The rate of infection at this point is:

\mathbf{m = \frac{V(t)}{t}}

\mathbf{m = \frac{20.745}{2.361}}

\mathbf{m = 8.79}

The rate of infection is <em>8.79 people per week</em>

Read more about graphs and functions at:

brainly.com/question/18806107

6 0
3 years ago
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