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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.R.84C

Use the given graphs of f and g to find each derivative. <IMAGE>
c. d/dx ((f(x) / g(x)) |x=3

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To find the derivative of the function \( \frac{f(x)}{g(x)} \) at \( x = 3 \), we will use the Quotient Rule. The Quotient Rule states that if you have a function \( h(x) = \frac{f(x)}{g(x)} \), then its derivative \( h'(x) \) is given by \( h'(x) = \frac{f'(x)g(x) - f(x)g'(x)}{(g(x))^2} \).
First, identify \( f(x) \) and \( g(x) \) from the graphs at \( x = 3 \). Determine the values of \( f(3) \) and \( g(3) \) from the graph.
Next, find the derivatives \( f'(x) \) and \( g'(x) \) at \( x = 3 \). This involves determining the slopes of the tangent lines to the graphs of \( f \) and \( g \) at \( x = 3 \).
Substitute the values \( f(3) \), \( g(3) \), \( f'(3) \), and \( g'(3) \) into the Quotient Rule formula: \( h'(3) = \frac{f'(3)g(3) - f(3)g'(3)}{(g(3))^2} \).
Simplify the expression obtained from the Quotient Rule to find the derivative of \( \frac{f(x)}{g(x)} \) at \( x = 3 \).

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Key Concepts

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

Derivative

The derivative of a function measures how the function's output value changes as its input value changes. It is defined as the limit of the average rate of change of the function over an interval as the interval approaches zero. Derivatives are fundamental in calculus for understanding rates of change and are denoted as f'(x) or df/dx.
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Derivatives

Quotient Rule

The Quotient Rule is a formula used to find the derivative of a function that is the quotient of two other functions. If h(x) = f(x) / g(x), the derivative h'(x) is given by h'(x) = (f'(x)g(x) - f(x)g'(x)) / (g(x))^2. This rule is essential when differentiating functions that are divided by one another.
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The Quotient Rule

Evaluating Derivatives at a Point

Evaluating a derivative at a specific point involves substituting the x-value into the derivative function. For example, to find d/dx (f(x) / g(x)) at x=3, you first apply the Quotient Rule to find the derivative and then substitute x=3 into the resulting expression. This process provides the instantaneous rate of change of the function at that particular point.
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