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Ch. 2 - Graphs and Functions
Lial - College Algebra 13th Edition
Lial13th EditionCollege AlgebraISBN: 9780136881063Not the one you use?Change textbook
Chapter 3, Problem 50

For each function, find (a)ƒ(x+h), (b)ƒ(x+h)-ƒ(x), and (c)[ƒ(x+h)-ƒ(x)]/h.See Example 4.
ƒ(x)=1/x2ƒ(x)=1/x^2

Verified step by step guidance
1
Start by writing the given function: \(f(x) = \frac{1}{x^2}\).
To find \(f(x+h)\), replace every \(x\) in the function with \((x+h)\), so write \(f(x+h) = \frac{1}{(x+h)^2}\).
Next, calculate \(f(x+h) - f(x)\) by subtracting the original function from the new expression: \(\frac{1}{(x+h)^2} - \frac{1}{x^2}\).
To simplify \(f(x+h) - f(x)\), find a common denominator, which is \(x^2 (x+h)^2\), and rewrite the expression as a single fraction.
Finally, to find \(\frac{f(x+h) - f(x)}{h}\), divide the simplified difference by \(h\), which means multiplying the fraction by \(\frac{1}{h}\).

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Key Concepts

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

Function Notation and Evaluation

Function notation, such as ƒ(x), represents a rule that assigns each input x to an output. Evaluating ƒ(x+h) means substituting x+h into the function in place of x, which helps analyze how the function behaves near x.
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Evaluating Composed Functions

Difference of Function Values

The expression ƒ(x+h) - ƒ(x) calculates the change in the function's output as the input changes from x to x+h. This difference is fundamental in understanding rates of change and forms the basis for concepts like the difference quotient.
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Difference Quotient and Its Role

The difference quotient [ƒ(x+h) - ƒ(x)]/h measures the average rate of change of the function over the interval from x to x+h. It is a key concept in calculus, used to approximate derivatives and analyze function behavior.
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Product, Quotient, and Power Rules of Logs