Math Problem Statement

find the inverse f1 f^{-1}\text{ }of f(x)=1x5f\left(x\right)=\frac{1}{x}-5

Solution

To find the inverse function f1(x)f^{-1}(x) for f(x)=1x5f(x) = \frac{1}{x} - 5, follow these steps:


Step 1: Replace f(x)f(x) with yy

Let y=f(x)y = f(x). This gives: y=1x5y = \frac{1}{x} - 5


Step 2: Swap xx and yy

For the inverse, interchange xx and yy: x=1y5x = \frac{1}{y} - 5


Step 3: Solve for yy

Rearrange the equation to isolate yy:

  1. Add 5 to both sides: x+5=1yx + 5 = \frac{1}{y}

  2. Take the reciprocal of both sides: y=1x+5y = \frac{1}{x + 5}


Step 4: Write the inverse function

The inverse function is: f1(x)=1x+5f^{-1}(x) = \frac{1}{x + 5}


Would you like to see a graph of f(x)f(x) and its inverse to verify? Let me know!

Related Questions

  1. How do you verify that f1(x)f^{-1}(x) is correct?
  2. Can you find the domain and range of f(x)f(x) and f1(x)f^{-1}(x)?
  3. What happens to f1(x)f^{-1}(x) as x5x \to -5?
  4. How does the horizontal asymptote of f(x)f(x) relate to the vertical asymptote of f1(x)f^{-1}(x)?
  5. What is the composition f(f1(x))f(f^{-1}(x)) and how does it simplify?

Tip

Always check the domain restrictions of the original function when finding its inverse to ensure they match.

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Math Problem Analysis

Mathematical Concepts

Inverse Functions
Algebra
Rational Functions

Formulas

f^{-1}(x) = \frac{1}{x + 5}

Theorems

Inverse Function Theorem

Suitable Grade Level

Grades 9-11