Math Problem Statement

Diketahui f(x) = x + 1 dan g(x) = x^2 - 1. Rumus fungsi (f/g)(x) adalah ....

Solution

To solve the problem, we need to find the formula for the composite function fg(x)\frac{f}{g}(x), where f(x)=x+1f(x) = x + 1 and g(x)=x21g(x) = x^2 - 1. Here are the steps:

Step 1: Understand the function

The division of two functions fg(x)\frac{f}{g}(x) is defined as: fg(x)=f(x)g(x)\frac{f}{g}(x) = \frac{f(x)}{g(x)}

Step 2: Substitute f(x)f(x) and g(x)g(x)

Given: f(x)=x+1,g(x)=x21f(x) = x + 1, \quad g(x) = x^2 - 1 Substitute these into the formula: fg(x)=x+1x21\frac{f}{g}(x) = \frac{x + 1}{x^2 - 1}

Step 3: Simplify the denominator

Note that x21x^2 - 1 can be factored as a difference of squares: x21=(x1)(x+1)x^2 - 1 = (x - 1)(x + 1) Thus: fg(x)=x+1(x1)(x+1)\frac{f}{g}(x) = \frac{x + 1}{(x - 1)(x + 1)}

Step 4: Simplify the fraction

Cancel x+1x + 1 in the numerator and denominator, provided x1x \neq -1 (to avoid division by zero): fg(x)=1x1,x1\frac{f}{g}(x) = \frac{1}{x - 1}, \quad x \neq -1

Final Answer:

The formula for fg(x)\frac{f}{g}(x) is: fg(x)=1x1,x1\frac{f}{g}(x) = \frac{1}{x - 1}, \quad x \neq -1

Would you like a detailed breakdown of this explanation or have any questions?


Here are 5 related questions:

  1. How do you handle undefined points in a function, such as x=1x = -1 in this case?
  2. What is the domain of fg(x)\frac{f}{g}(x) given this solution?
  3. How would this change if f(x)=x2+2x+1f(x) = x^2 + 2x + 1?
  4. What happens if g(x)g(x) has a repeated factor in its denominator?
  5. How can this concept be extended to division of more complex functions?

Tip: Always check for restrictions in the domain, especially where the denominator equals zero.

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Math Problem Analysis

Mathematical Concepts

Function Operations
Simplification of Rational Expressions

Formulas

(f/g)(x) = f(x) / g(x)
Difference of Squares: a^2 - b^2 = (a - b)(a + b)

Theorems

Domain Restrictions in Rational Functions

Suitable Grade Level

Grades 10-12