Math Problem Statement

Find the inverse of the following functions: 1) f(x) = 4x + 3, 2) f(x) = 1 / (5x - 6), 3) f(x) = (x - 7) / (3x + 1)

Solution

Let's solve the problem of finding the inverse of the three functions given in the image one by one:

1. Find the inverse of f(x)=4x+3f(x) = 4x + 3

Steps:

  1. Replace f(x)f(x) with yy: y=4x+3y = 4x + 3
  2. Swap xx and yy: x=4y+3x = 4y + 3
  3. Solve for yy: x3=4yx - 3 = 4y y=x34y = \frac{x - 3}{4} Thus, the inverse is: f1(x)=x34f^{-1}(x) = \frac{x - 3}{4}

2. Find the inverse of f(x)=15x6f(x) = \frac{1}{5x - 6}

Steps:

  1. Replace f(x)f(x) with yy: y=15x6y = \frac{1}{5x - 6}
  2. Swap xx and yy: x=15y6x = \frac{1}{5y - 6}
  3. Solve for yy: x(5y6)=1x(5y - 6) = 1 5xy6x=15xy - 6x = 1 5xy=6x+15xy = 6x + 1 y=6x+15xy = \frac{6x + 1}{5x} Thus, the inverse is: f1(x)=6x+15xf^{-1}(x) = \frac{6x + 1}{5x}

3. Find the inverse of f(x)=x73x+1f(x) = \frac{x - 7}{3x + 1}

Steps:

  1. Replace f(x)f(x) with yy: y=x73x+1y = \frac{x - 7}{3x + 1}
  2. Swap xx and yy: x=y73y+1x = \frac{y - 7}{3y + 1}
  3. Solve for yy: x(3y+1)=y7x(3y + 1) = y - 7 3xy+x=y73xy + x = y - 7 3xyy=x73xy - y = -x - 7 y(3x1)=x7y(3x - 1) = -x - 7 y=x73x1y = \frac{-x - 7}{3x - 1} Thus, the inverse is: f1(x)=x73x1f^{-1}(x) = \frac{-x - 7}{3x - 1}

Would you like further clarification on any of these steps? Here are some related questions you might find useful:

  1. What are the general steps to find the inverse of any function?
  2. How can you verify if the computed inverse is correct?
  3. What are the conditions for a function to have an inverse?
  4. How do domain and range change when finding an inverse?
  5. Can every function have an inverse? Why or why not?

Tip: To check if the inverse is correct, composing the function and its inverse should return xx. That is, f(f1(x))=xf(f^{-1}(x)) = x and f1(f(x))=xf^{-1}(f(x)) = x.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Function Inversion
Algebraic Manipulation

Formulas

Inverse of a linear function: f(x) = ax + b -> f^-1(x) = (x - b)/a
Inverse of a rational function: f(x) = (ax + b)/(cx + d) -> f^-1(x) = (dx - b)/(a - cx)

Theorems

Function Inversion Theorem

Suitable Grade Level

College Level