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Ch. 3 - Derivatives
Briggs - Calculus: Early Transcendentals 3rd Edition
Briggs3rd EditionCalculus: Early TranscendentalsISBN: 9780136847243Not the one you use?Change textbook
Chapter 3, Problem 91a

If possible, evaluate the following derivatives using the graphs of f and f'. <IMAGE>
a. (f^-1)'(7)

Verified step by step guidance
1
To find the derivative of the inverse function at a point, we use the formula: \((f^{-1})'(b) = \frac{1}{f'(a)}\), where \(f(a) = b\).
Identify the point \(b = 7\) on the graph of \(f\). Find the corresponding \(a\) such that \(f(a) = 7\).
Once you have found \(a\), locate \(f'(a)\) on the graph of \(f'\). This is the slope of the tangent to \(f\) at \(a\).
Substitute \(f'(a)\) into the formula \((f^{-1})'(7) = \frac{1}{f'(a)}\) to find the derivative of the inverse function at 7.
Ensure that \(f'(a) \neq 0\) to avoid division by zero, which would indicate that the inverse function is not differentiable at that point.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Inverse Function Theorem

The Inverse Function Theorem states that if a function f is continuous and differentiable, and its derivative f' is non-zero at a point, then the inverse function f^-1 exists locally around that point. The derivative of the inverse function can be calculated using the formula (f^-1)'(y) = 1 / f'(f^-1(y)), which relates the derivatives of the function and its inverse.
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Derivative Interpretation

The derivative of a function at a point represents the slope of the tangent line to the graph of the function at that point. In the context of the question, understanding how to interpret the derivative graphically is crucial for evaluating (f^-1)'(7), as it involves analyzing the behavior of f and its inverse at specific values.
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Graphical Analysis of Functions

Graphical analysis involves examining the graphs of functions and their derivatives to understand their behavior. For the given question, one must analyze the graph of f to find the corresponding x-value for f(x) = 7, and then use the graph of f' to determine the slope at that point, which is essential for calculating the derivative of the inverse function.
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