Math Problem Statement

write the inverse of the function f(x) = 2- (12/(x+5))

Solution

To find the inverse of the function f(x)=212x+5f(x) = 2 - \frac{12}{x+5}, we follow these steps:

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

y=212x+5y = 2 - \frac{12}{x+5}

Step 2: Swap xx and yy.

x=212y+5x = 2 - \frac{12}{y+5}

Step 3: Solve for yy in terms of xx.

  1. Subtract 2 from both sides: x2=12y+5x - 2 = -\frac{12}{y+5}

  2. Multiply through by (y+5)-(y+5) to eliminate the fraction: (x2)(y+5)=12-(x-2)(y+5) = 12

  3. Distribute the (x2)-(x-2): (x2)y5(x2)=12-(x-2)y - 5(x-2) = 12

  4. Rearrange to isolate yy: (x2)y=12+5(x2)-(x-2)y = 12 + 5(x-2)

    Simplify the right-hand side: (x2)y=12+5x10-(x-2)y = 12 + 5x - 10

    (x2)y=5x+2-(x-2)y = 5x + 2

  5. Solve for yy: y=(5x+2)(x2)y = \frac{-(5x+2)}{-(x-2)}

    Simplify the negatives: y=5x+2x2y = \frac{5x+2}{x-2}

Step 4: Replace yy with f1(x)f^{-1}(x).

f1(x)=5x+2x2f^{-1}(x) = \frac{5x+2}{x-2}

Final Answer:

The inverse of f(x)=212x+5f(x) = 2 - \frac{12}{x+5} is: f1(x)=5x+2x2.f^{-1}(x) = \frac{5x+2}{x-2}.


Do you want a verification or further explanation?
Here are some related questions to consider:

  1. How can we verify that this is the correct inverse?
  2. What is the domain and range of f(x)f(x) and f1(x)f^{-1}(x)?
  3. How do the graphs of f(x)f(x) and f1(x)f^{-1}(x) relate geometrically?
  4. What happens to the function at x=5x = -5, and how does it affect the inverse?
  5. Are there any restrictions on xx for the inverse function?

Tip: Always check the domain and range of a function and its inverse to ensure they correspond appropriately.

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Math Problem Analysis

Mathematical Concepts

Algebra
Inverse Functions
Rational Functions

Formulas

Inverse of a function: Swap x and y, then solve for y

Theorems

Property of inverse functions: f(f^(-1)(x)) = x

Suitable Grade Level

Grades 10-12