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Ch. 8 - Sequences, Induction, and Probability
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514Not the one you use?Change textbook
Chapter 9, Problem 53

Find f(x + h) − f(x)/h and simplify. f(x) = x4+7

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Start with the given function: \(f(x) = x^4 + 7\).
Find the expression for \(f(x + h)\) by substituting \(x + h\) into the function: \(f(x + h) = (x + h)^4 + 7\).
Expand the binomial \((x + h)^4\) using the binomial theorem or by repeated multiplication.
Form the difference quotient by subtracting \(f(x)\) from \(f(x + h)\) and then dividing by \(h\): \(\frac{f(x + h) - f(x)}{h} = \frac{(x + h)^4 + 7 - (x^4 + 7)}{h}\).
Simplify the numerator by canceling out like terms and then simplify the entire expression by factoring and reducing where possible.

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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

Understanding function notation f(x) is essential to evaluate expressions like f(x + h). This involves substituting the input variable x with (x + h) in the function's formula and simplifying the resulting expression.
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Difference Quotient

The difference quotient, given by (f(x + h) - f(x)) / h, measures the average rate of change of the function over the interval from x to x + h. It is foundational for understanding derivatives and requires careful algebraic manipulation.
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Polynomial Expansion and Simplification

Expanding polynomials like (x + h)^4 using binomial expansion or other methods is necessary to simplify the difference quotient. Combining like terms and factoring where possible helps to reduce the expression to its simplest form.
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