Table of contents
- 0. Functions7h 52m
- Introduction to Functions16m
- Piecewise Functions10m
- Properties of Functions9m
- Common Functions1h 8m
- Transformations5m
- Combining Functions27m
- Exponent rules32m
- Exponential Functions28m
- Logarithmic Functions24m
- Properties of Logarithms34m
- Exponential & Logarithmic Equations35m
- Introduction to Trigonometric Functions38m
- Graphs of Trigonometric Functions44m
- Trigonometric Identities47m
- Inverse Trigonometric Functions48m
- 1. Limits and Continuity2h 2m
- 2. Intro to Derivatives1h 33m
- 3. Techniques of Differentiation3h 18m
- 4. Applications of Derivatives2h 38m
- 5. Graphical Applications of Derivatives6h 2m
- 6. Derivatives of Inverse, Exponential, & Logarithmic Functions2h 37m
- 7. Antiderivatives & Indefinite Integrals1h 26m
- 8. Definite Integrals4h 44m
- 9. Graphical Applications of Integrals2h 27m
- 10. Physics Applications of Integrals 2h 22m
2. Intro to Derivatives
Basic Graphing of the Derivative
Problem 3.1.53b
Textbook Question
Owlet talons Let L (t) equal the average length (in mm) of the middle talon on an Indian spotted owlet that is t weeks old, as shown in the figure.<IMAGE>
b. Estimate the value of L'(a) for a ≥ 4 . What does this tell you about the talon lengths on these birds? (Source: ZooKeys, 132, 2011)

1
Step 1: Understand that L'(a) represents the derivative of the function L(t) at t = a, which gives the rate of change of the talon length with respect to time at that specific week.
Step 2: To estimate L'(a) for a ≥ 4, identify two points on the graph of L(t) that are close to t = a. These points will help you calculate the average rate of change, which approximates the derivative.
Step 3: Use the formula for the average rate of change between two points (t1, L(t1)) and (t2, L(t2)) on the graph: \( \frac{L(t2) - L(t1)}{t2 - t1} \). Choose t1 and t2 such that t1 < a < t2.
Step 4: Substitute the values of L(t1) and L(t2) from the graph into the formula to calculate the average rate of change, which serves as an estimate for L'(a).
Step 5: Interpret the result: A positive L'(a) indicates that the talon length is increasing at week a, while a negative L'(a) would indicate a decrease. The magnitude of L'(a) tells you how quickly the talon length is changing.

This video solution was recommended by our tutors as helpful for the problem above
Video duration:
6mPlay a video:
Was this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Derivative
The derivative of a function measures the rate at which the function's value changes as its input changes. In this context, L'(a) represents the instantaneous rate of change of the average length of the talon with respect to time (weeks). A positive derivative indicates that the talon length is increasing, while a negative derivative suggests it is decreasing.
Recommended video:
Derivatives
Average Rate of Change
The average rate of change of a function over an interval gives a general idea of how the function behaves between two points. For the function L(t), the average rate of change from t = 4 to t = a can provide insights into how the average talon length evolves as the owlet ages, helping to contextualize the derivative's value.
Recommended video:
Average Value of a Function
Biological Growth Patterns
Understanding biological growth patterns is essential for interpreting the results of L'(a). In many species, growth rates can vary with age due to factors like maturity and environmental influences. Analyzing L'(a) in this context can reveal whether the talon lengths are stabilizing, accelerating, or decelerating as the owlets mature.
Recommended video:
Sigma Notation Example 1
Watch next
Master Graphing The Derivative with a bite sized video explanation from Nick
Start learning