Problem 8

Question

Political Membership \(\quad\) The function \(m\) gives the number of members in a political organization \(t\) years after its founding. a. What are the units on \(m^{\prime}(10)\) ? b. Is it possible for \(m^{\prime}(10)\) to be negative? Explain.

Step-by-Step Solution

Verified
Answer
a. Units are members per year. b. Yes, it can be negative if membership is decreasing at that time.
1Step 1: Understand the Derivative
The derivative \(m'(t)\) represents the rate of change of membership with respect to time, in years, after the organization's founding. It tells us how fast or slow the membership is changing at a particular time \(t\).
2Step 2: Determine the Units of the Derivative
The units of \(m'(10)\) can be found by considering the function \(m(t)\) itself. Since \(m\) is the number of members and \(t\) is in years, the units of \(m'(t)\) are "members per year." Thus, the units on \(m'(10)\) are members per year.
3Step 3: Consider the Possibility of a Negative Derivative
\(m'(t)\) being negative would mean that the number of members is decreasing at time \(t\). This is possible if the organization is losing members. Therefore, \(m'(10)\) can be negative if the number of members is declining at \(t = 10\) years.

Key Concepts

Rate of ChangeUnits of MeasurementDecreasing Functions
Rate of Change
The rate of change is a fundamental concept in calculus. When we talk about the rate of change in the context of a function, we're discussing how one quantity changes in relation to another. In the case of the political membership function, the derivative \(m'(t)\) represents how the number of members is changing over time. It helps to determine whether the membership is increasing or decreasing at a specific point in time. Understanding the rate of change involves:
  • Recognizing how fast or slow a change occurs.
  • Identifying whether the change is positive (increasing) or negative (decreasing).
At \(t = 10\), if \(m'(10) = 5\), it means the membership is increasing by 5 members each year at that point. Conversely, if \(m'(10) = -5\), it means it's decreasing by 5 members per year. Thus, the rate of change provides a snapshot of dynamic processes within the organization.
Units of Measurement
Understanding units of measurement is crucial for interpreting derivatives correctly. Units tell us what the numbers in calculations actually signify, providing context to mathematical results. In the given problem, the function \(m(t)\) outputs the number of members and takes years as an input, so it's expressed in terms of 'members'. To find the units of \(m'(t)\):
  • The numerator corresponds to the change in members.
  • The denominator represents the change in years.
Thus, \(m'(t)\)'s units are 'members per year'. This tells us how much the number of members changes every year. By understanding and applying the correct units, we gain insight into the real-world implications of the mathematical calculations.
Decreasing Functions
A decreasing function describes a scenario where the output value decreases as the input value increases. This concept is vital when examining situations where quantities are reducing over time.When we see that \(m'(t)\) is negative, it indicates that the membership is declining at time \(t\). This means that:
  • The organization's membership is losing members rather than gaining them.
  • Each unit increase in time results in a decrease in the number of members.
Knowing whether a function is increasing or decreasing allows for insightful predictions and decisions. If the political organization wants to reverse this trend, understanding these patterns becomes essential for strategic planning and corrective actions. By recognizing decreasing functions, stakeholders can better manage resources and plan efforts to turn the situation around.