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Ch. 3 - Derivatives
Briggs - Calculus: Early Transcendentals 3rd Edition
Briggs3rd EditionCalculus: Early TranscendentalsISBN: 9780136847243Non è quello che usi tu?Cambia libro di testo
Capitolo 3, Problema 3.9.47

15–48. Derivatives Find the derivative of the following functions.
f(x) = 2^x/2^x+1

Guida verificata passo dopo passo
1
Step 1: Identify the function f(x) = \( \frac{2^x}{2^x + 1} \). This is a quotient of two functions, so we will use the quotient rule to find the derivative.
Step 2: Recall the quotient rule for derivatives: If you have a function \( g(x) = \frac{u(x)}{v(x)} \), then the derivative \( g'(x) \) is given by \( \frac{u'(x)v(x) - u(x)v'(x)}{(v(x))^2} \).
Step 3: Assign \( u(x) = 2^x \) and \( v(x) = 2^x + 1 \). Now, find the derivatives \( u'(x) \) and \( v'(x) \).
Step 4: The derivative of \( u(x) = 2^x \) is \( u'(x) = 2^x \ln(2) \) because the derivative of \( a^x \) is \( a^x \ln(a) \). The derivative of \( v(x) = 2^x + 1 \) is \( v'(x) = 2^x \ln(2) \) since the derivative of a constant is zero.
Step 5: Substitute \( u(x), u'(x), v(x), \) and \( v'(x) \) into the quotient rule formula: \( f'(x) = \frac{2^x \ln(2) (2^x + 1) - 2^x (2^x \ln(2))}{(2^x + 1)^2} \). Simplify the expression to find the derivative.

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A derivative represents the rate of change of a function with respect to its variable. It is a fundamental concept in calculus that provides information about the slope of the tangent line to the function's graph at any given point. Understanding how to compute derivatives is essential for analyzing the behavior of functions, including their increasing or decreasing nature.
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