Math Problem Statement

If x is added to 4 and then multiplied by 2, then the function is f left parenthesis x right parenthesis equals 2 left parenthesis x plus 4 right parenthesis.

What are the steps to find the inverse to this function?

Solution

To find the inverse of the function f(x)=2(x+4)f(x) = 2(x + 4), follow these steps:

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

Write the function as: y=2(x+4)y = 2(x + 4)

Step 2: Swap xx and yy

To find the inverse, swap xx and yy: x=2(y+4)x = 2(y + 4)

Step 3: Solve for yy

Now solve the equation for yy.

  1. Divide both sides by 2 to isolate the y+4y + 4 term: x2=y+4\frac{x}{2} = y + 4

  2. Subtract 4 from both sides: y=x24y = \frac{x}{2} - 4

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

The inverse function is: f1(x)=x24f^{-1}(x) = \frac{x}{2} - 4

Final Answer:

f1(x)=x24f^{-1}(x) = \frac{x}{2} - 4


Would you like further explanation on any of the steps? Here are some related questions you might find interesting:

  1. What does it mean geometrically for a function and its inverse?
  2. How can you verify that two functions are inverses of each other?
  3. What is the domain and range of the function f(x)=2(x+4)f(x) = 2(x + 4)?
  4. How do you graph a function and its inverse?
  5. What happens if a function is not one-to-one?

Tip: Always remember that for a function to have an inverse, it must be one-to-one (meaning each xx-value corresponds to exactly one yy-value).

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Math Problem Analysis

Mathematical Concepts

Algebra
Functions
Inverse Functions

Formulas

f(x) = 2(x + 4)
f^{-1}(x) = (x/2) - 4

Theorems

Inverse Function Theorem

Suitable Grade Level

Grades 8-10