Explore IDNLearn.com's extensive Q&A database and find the answers you're looking for. Receive prompt and accurate responses to your questions from our community of knowledgeable professionals ready to assist you at any time.

Find the difference quotient [tex]\(\frac{f(x+h)-f(x)}{h}\)[/tex], where [tex]\(h \neq 0\)[/tex], for the function

[tex]\[ f(x) = \frac{x}{x-1} \][/tex]

Simplify your answer as much as possible.


Sagot :

To find the difference quotient [tex]\(\frac{f(x+h)-f(x)}{h}\)[/tex] for the function [tex]\(f(x) = \frac{x}{x-1}\)[/tex], we proceed as follows:

1. Substitute [tex]\(x + h\)[/tex] into the function:
[tex]\[ f(x + h) = \frac{x + h}{(x + h) - 1} = \frac{x + h}{x + h - 1} \][/tex]

2. Form the difference quotient:
[tex]\[ \frac{f(x + h) - f(x)}{h} = \frac{\frac{x + h}{x + h - 1} - \frac{x}{x - 1}}{h} \][/tex]

3. Find a common denominator for the fractions in the numerator:
[tex]\[ \frac{x + h}{x + h - 1} = \frac{(x + h)(x - 1)}{(x + h - 1)(x - 1)} \][/tex]
[tex]\[ \frac{x}{x - 1} = \frac{x(x + h - 1)}{(x + h - 1)(x - 1)} \][/tex]

4. Combine the fractions:
[tex]\[ \frac{f(x + h) - f(x)}{h} = \frac{\frac{(x + h)(x - 1) - x(x + h - 1)}{(x + h - 1)(x - 1)}}{h} \][/tex]

5. Simplify the numerator:
[tex]\[ (x + h)(x - 1) - x(x + h - 1) = (x^2 - x + hx - h) - (x^2 + hx - x) = -x + hx - h + x = h(x - 1) \][/tex]

So, the expression simplifies to:
[tex]\[ \frac{h(x - 1)}{h(x + h - 1)(x - 1)} \][/tex]

6. Cancel the [tex]\(h\)[/tex] in the numerator and denominator:
[tex]\[ \frac{h(x - 1)}{h(x + h - 1)(x - 1)} = \frac{(x - 1)}{(x + h - 1)(x - 1)} = \frac{1}{x + h - 1} \][/tex]

7. Final simplified difference quotient:
[tex]\[ -\frac{1}{hx - h + x^2 - 2x + 1} \][/tex]

Thus, the difference quotient [tex]\(\frac{f(x+h)-f(x)}{h}\)[/tex] for the function [tex]\(f(x) = \frac{x}{x-1}\)[/tex] simplifies to:
[tex]\[ \frac{(f(x+h) - f(x))}{h} = -\frac{1}{hx - h + x^2 - 2x + 1} \][/tex]