2010 AP Calculus AB Free Response #2

Allen Tsao The STEM Coach
29 Oct 201813:12
EducationalLearning
32 Likes 10 Comments

TLDRIn this video, Alan from Bothell Stem Coach dives into the 2010 AP Calculus AB Free Response questions, focusing on a problem involving a zoo's one-day contest to name a baby elephant. The problem presents a differentiable function e(t) that models the number of contest entries deposited in a box over time. Alan uses the secant line method to approximate the rate of entries per hour at t=6 and the trapezoid rule to approximate the average value of the function over the interval from noon to 8 PM. He also explores the rate at which entries were processed, using integration to find the total number of entries processed by midnight. The video concludes with a maximization problem to determine when the entries were processed most quickly, using the first derivative test to find critical points and comparing them to endpoints. Alan's approach to solving these calculus problems is methodical and engaging, providing viewers with a clear understanding of the concepts and steps involved.

Takeaways
  • ๐Ÿ˜ Alan is discussing a 2010 AP Calculus AB free response question related to a zoo's baby elephant naming contest.
  • โฑ The number of contest entries deposited in a box is modeled by a differentiable function e(t) for t hours between noon and 8 PM.
  • ๐Ÿ“ˆ To find the rate of entries being deposited at t=6 hours, Alan uses the secant line method by calculating the slope between e(7) and e(5).
  • ๐Ÿ“Š Alan approximates the value of the function e(t) over the 8-hour period using a trapezoid sum, which involves averaging the values at different points and multiplying by the interval width.
  • ๐Ÿงฎ The average number of entries per hour is calculated to be approximately 10.438 when rounded to two decimal places.
  • ๐Ÿ“š The volunteers begin processing entries at 8 PM, and the rate of processing is modeled by the function P(t), which Alan needs to integrate from 8 to 12 to find the total number of entries processed.
  • ๐Ÿ” To find the time when entries were processed most quickly, Alan looks for the maximum rate of P(t) by taking the derivative and finding critical points where P'(t) = 0.
  • ๐Ÿ“ˆ Alan identifies two potential critical points at t = 9.184 and t = 10.816, but after analyzing them and the endpoints, concludes that the maximum rate occurs at t = 12.
  • ๐Ÿค” Alan acknowledges a potential error in his previous calculation of the rate of entries per hour, suggesting he may have made a mistake while using a calculator.
  • ๐Ÿ“‹ The final answer indicates that the maximum rate of processing entries occurs at t = 12, and Alan emphasizes the importance of checking endpoints when finding absolute maxima.
  • ๐Ÿ‘ Alan encourages viewers to comment, like, or subscribe for more content and offers free homework help on Twitch and Discord.
Q & A
  • What is the context of the video script?

    -The video script is about a tutorial on AP Calculus, specifically focusing on a free response question from the 2010 AP Calculus AB exam. The problem involves modeling the number of entries for a contest to name a baby elephant over time.

  • What is the function used to model the number of entries in the box over time?

    -The function used to model the number of entries in the box over time is denoted by 'e(t)', where 't' represents the number of hours past noon.

  • How is the rate of entries being deposited at time t=6 hours approximated?

    -The rate of entries being deposited at time t=6 hours is approximated using the secant line method, which involves calculating the slope between e(7) and e(5) and then dividing by the change in t, which is 2 hours in this case.

  • What mathematical concept is used to approximate the total number of entries over the 8-hour period?

    -The concept of the average value, specifically using the trapezoid sum, is used to approximate the total number of entries over the 8-hour period.

  • What is the formula for the average value using the trapezoid sum?

    -The formula for the average value using the trapezoid sum is given by (1/8) * โˆ‘(e(t) * ฮ”t), where ฮ”t is the width of each interval, and the summation is taken over the four subintervals.

  • How many hundreds of entries were processed by midnight according to the model?

    -According to the model, 700 hundreds of entries were processed by midnight.

  • What function is used to model the rate at which entries are being processed?

    -The function used to model the rate at which entries are being processed is denoted by P(t), and it is given by the polynomial P(t) = 3t^3 - 30t^2 + 298t - 976.

  • What is the method used to find the time when the entries are being processed most quickly?

    -The method used to find the time when the entries are being processed most quickly is to find the critical points of the function P(t) by taking its derivative and setting it to zero, then comparing the values at the critical points and endpoints to determine the absolute maximum.

  • What is the significance of the endpoints in finding the absolute maximum rate of processing entries?

    -The endpoints are significant because they must be included in the comparison when determining the absolute maximum rate. Even if a point is a local maximum, the value at the endpoints could potentially be higher, and thus they cannot be excluded.

  • What was the mistake made in the calculation of the average number of entries per hour?

    -The mistake was likely a misentry into the calculator or a slight error in the arithmetic process. The presenter acknowledged that the math was correct, but there was a discrepancy in the final numerical result.

  • What additional resources does the presenter offer for further help?

    -The presenter offers free homework help on platforms like Twitch and Discord, and encourages viewers to comment, like, or subscribe for more content.

  • What is the final conclusion about the time when the entries were being processed most quickly?

    -The final conclusion is that the entries were being processed most quickly at time T equals 12, which corresponds to 12 hours past noon.

Outlines
00:00
๐Ÿ“Š Calculating Entry Rates and Averages - AP Calculus AB

In this segment, Alan from Bothell Stem Coach is discussing a problem from the 2010 AP Calculus AB free response section. The problem involves a zoo's one-day contest to name a baby elephant and the rate at which entries are deposited in a box over time. Alan uses the data from a table to approximate the rate of entries per hour at a specific time, t=6, by calculating the secant line slope between the points (5, e(5)) and (7, e(7)). He then uses a trapezoid sum to approximate the value of an integral from 0 to 8, which represents the average number of entries over the 8-hour period. The integral is solved using the function e(t), and the average number of entries per hour is determined to be approximately 10.43 hundreds of entries per hour.

05:01
๐Ÿงฎ Processing Entries and Maximizing Rates - AP Calculus AB

The second paragraph deals with the processing of the contest entries. Alan explains how to calculate the total number of entries processed by midnight by integrating the rate function P(t) from 8 to 12, as this is the time frame when entries were being processed. He uses the function P(t) = t^3 - 30t^2 + 298t - 976 to find the integral and determines that 716 hundreds of entries were processed. To find when the entries were processed most quickly, Alan looks for the maximum rate of P(t). He takes the derivative P'(t) = 3t^2 - 60t + 298 to find critical points and uses a graph to identify that the maximum rate occurs at t = 12, which corresponds to an increasing function and the highest value on the graph. Alan corrects a previous calculation error regarding the average number of entries per hour, emphasizing the importance of checking calculations.

10:03
๐Ÿ” Reflecting on the Calculation Process - AP Calculus AB

In the final paragraph, Alan reflects on the calculation process and encourages viewers to consider all points, including minima and maxima, when finding absolute maximum values. He acknowledges that he initially excluded a minimum point from his comparison but reminds viewers that endpoints should always be included in such calculations. Alan concludes by summarizing the findings: an average of 700 entries were processed between noon and 8:00 p.m., and the entries were processed most quickly at t = 12. He invites viewers to engage with the content by leaving comments, liking, or subscribing and mentions that he offers free homework help on Twitch and Discord. The video ends with an invitation to join him in the next video session.

Mindmap
Keywords
๐Ÿ’กAP Calculus
AP Calculus is a high school mathematics course and examination offered by the College Board. It is designed to be equivalent to a college-level calculus course and is often taken by students aiming to demonstrate their advanced mathematical abilities. In the video, the presenter is discussing the 2010 AP Calculus AB free response questions, which are part of the exam.
๐Ÿ’กFree Response Questions
Free response questions are a type of assessment commonly used in exams like AP Calculus, where students must provide a detailed answer to a question. These questions often require more than just selecting an answer; they involve problem-solving, critical thinking, and the ability to communicate mathematical reasoning. The video script discusses the free response questions from the 2010 AP Calculus AB exam.
๐Ÿ’กDifferentiable Function
A differentiable function is a mathematical function that has a derivative at every point in its domain. This means that the function has a tangent line at every point, and the rate of change of the function is well-defined. In the video, the number of entries in a box over time is modeled by a differentiable function, which allows the presenter to calculate rates of change, such as the rate of entries being deposited per hour.
๐Ÿ’กSecant Line
A secant line is a straight line that intersects a function at two or more points. In calculus, the slope of the secant line between two points on a curve can be used to approximate the derivative or the rate of change of the function at a specific point. The presenter uses the secant line concept to approximate the rate of entries being deposited at T equals 6 hours.
๐Ÿ’กTrapezoid Sum
The trapezoid sum is a method used in numerical integration to approximate the definite integral of a function. It involves breaking the area under the curve into trapezoids and summing their areas. In the video, the presenter uses the trapezoid sum to approximate the value of an integral related to the number of entries over a given interval.
๐Ÿ’กAverage Value
The average value of a function over an interval is a measure of the central tendency of the function's values over that interval. It is calculated by integrating the function over the interval and dividing by the length of the interval. In the context of the video, the presenter is finding the average number of entries in the box between noon and 8:00 p.m.
๐Ÿ’กIntegral
In calculus, an integral is a mathematical concept that represents the area under the curve of a function. It is the reverse process of differentiation and is used to find the accumulated quantity, such as the total number of entries processed over a period of time. The presenter calculates the total number of entries by integrating the rate function from 8 to 12 hours.
๐Ÿ’กDerivative
The derivative of a function at a point is the rate at which the function's value changes with respect to changes in its input. It is a fundamental concept in calculus and can be used to find the maximum or minimum values of a function. The presenter finds the derivative of the processing rate function to determine when the entries are being processed most quickly.
๐Ÿ’กCritical Numbers
Critical numbers are the values of the independent variable (often denoted as 'x' or 'T' in the video) at which the derivative of a function is either zero or undefined. These points are potential locations for local maxima or minima of the function. The presenter uses critical numbers to find the time when the rate of entry processing is the highest.
๐Ÿ’กFirst Derivative Test
The first derivative test is a method used to determine whether a critical number corresponds to a local maximum, local minimum, or neither. It involves analyzing the sign changes of the derivative around the critical number. In the video, the presenter uses the first derivative test to identify the nature of the critical points found when maximizing the processing rate function.
๐Ÿ’กEndpoints
In the context of integration and optimization problems, endpoints refer to the starting and ending values of the interval being considered. When finding the absolute maximum or minimum of a function over an interval, it is important to evaluate the function at the endpoints as well, as the maximum or minimum could occur at these points. The presenter emphasizes the importance of including endpoints when finding the absolute maximum rate of entry processing.
Highlights

Alan with Bothell stem coach is discussing the 2010 AP Calculus AB free response questions.

The context involves a zoo-sponsored contest to name a new baby elephant, with entries deposited in a special box.

A differentiable function e(t) models the number of entries in the box t hours after noon, with data provided in a table.

The task is to approximate the rate of entries being deposited per hour at t = 6 hours using the secant line method.

The rate at t = 6 is calculated to be 4 hundred entries per hour.

A trapezoid sum is used to approximate the value of the integral from 0 to 8 hours, representing the total entries.

The average number of entries over the 8-hour period is calculated to be approximately 10.438 hundred entries.

The function P(t) models the rate at which entries are processed, with an integral from 8 to 12 hours to find the total processed entries.

The total number of entries processed is found to be 616 hundreds of entries.

To find the time when entries were processed most quickly, the derivative of P(t) is taken and critical points are identified.

Two potential critical points are found at t = 9.184 and t = 10.816, with further analysis required to determine the maximum rate.

The first derivative test is used to identify the nature of the critical points (maximum or minimum).

Endpoints are included in the analysis to ensure the absolute maximum is captured.

The maximum rate of processing entries is determined to be at t = 12 hours.

A discrepancy is noted in the calculation of the average number of entries per hour, suggesting a possible error in the calculation or calculator entry.

Alan offers free homework help on Twitch and Discord for further assistance.

The video concludes with an invitation for viewers to comment, like, subscribe, and engage with the content.

Transcripts
Rate This

5.0 / 5 (0 votes)

Thanks for rating: