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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 3.10.38

Evaluate the derivative of the following functions.
f(x) = sin(tan-1 (ln x))

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First, identify the outermost function in the composition. Here, the function is f(x) = sin(u), where u = tan^(-1)(ln(x)).
Apply the chain rule for derivatives, which states that the derivative of a composite function f(g(x)) is f'(g(x)) * g'(x). In this case, differentiate sin(u) with respect to u, which gives cos(u).
Next, differentiate the inner function u = tan^(-1)(ln(x)) with respect to x. Start by differentiating tan^(-1)(v) with respect to v, which is 1/(1+v^2). Here, v = ln(x).
Now, differentiate ln(x) with respect to x, which is 1/x. Combine this with the previous step to find the derivative of u with respect to x: (1/(1+(ln(x))^2)) * (1/x).
Finally, combine the results using the chain rule: f'(x) = cos(tan^(-1)(ln(x))) * (1/(1+(ln(x))^2)) * (1/x). This is the derivative of the given function.

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Key Concepts

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

Chain Rule

The Chain Rule is a fundamental principle in calculus used to differentiate composite functions. It states that if a function y is composed of two functions u and v, then the derivative of y with respect to x can be found by multiplying the derivative of y with respect to u by the derivative of u with respect to x. This rule is essential for evaluating derivatives of functions like f(x) = sin(tan<sup>-1</sup>(ln x)), where multiple functions are nested.
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Inverse Trigonometric Functions

Inverse trigonometric functions, such as tan<sup>-1</sup>(x), are the functions that reverse the action of the standard trigonometric functions. They are crucial in calculus for finding angles when given a ratio of sides in a right triangle. Understanding how to differentiate these functions is vital when evaluating derivatives involving them, as they have specific derivative formulas that must be applied correctly.
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Derivatives of Other Inverse Trigonometric Functions

Natural Logarithm

The natural logarithm, denoted as ln(x), is the logarithm to the base e, where e is approximately 2.71828. It is an important function in calculus, particularly in differentiation and integration. The derivative of ln(x) is 1/x, which is a key component when differentiating functions that include the natural logarithm, such as ln(x) in the given function f(x).
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