Math Problem Statement

The 1 first

Find the inverse of the following functions: 1. m(x) = 7x - 5, 2. f(x) = 3x - 8

Solution

To find the inverse of the given functions, we'll follow the standard steps. Let's handle each function separately:

1. Inverse of m(x)=7x5m(x) = 7x - 5

Step-by-Step Process:

  1. Replace m(x)m(x) with yy:
    y=7x5y = 7x - 5

  2. Swap xx and yy (this is the key step to finding the inverse):
    x=7y5x = 7y - 5

  3. Solve for yy:
    Add 5 to both sides:
    x+5=7yx + 5 = 7y
    Now divide both sides by 7:
    y=x+57y = \frac{x + 5}{7}

  4. Replace yy with m1(x)m^{-1}(x) to denote the inverse function:
    m1(x)=x+57m^{-1}(x) = \frac{x + 5}{7}

So, the inverse of m(x)=7x5m(x) = 7x - 5 is m1(x)=x+57m^{-1}(x) = \frac{x + 5}{7}.


2. Inverse of f(x)=3x8f(x) = 3x - 8

Step-by-Step Process:

  1. Replace f(x)f(x) with yy:
    y=3x8y = 3x - 8

  2. Swap xx and yy:
    x=3y8x = 3y - 8

  3. Solve for yy:
    Add 8 to both sides:
    x+8=3yx + 8 = 3y
    Now divide both sides by 3:
    y=x+83y = \frac{x + 8}{3}

  4. Replace yy with f1(x)f^{-1}(x) to denote the inverse function:
    f1(x)=x+83f^{-1}(x) = \frac{x + 8}{3}

So, the inverse of f(x)=3x8f(x) = 3x - 8 is f1(x)=x+83f^{-1}(x) = \frac{x + 8}{3}.


Would you like a detailed breakdown of any of these steps? Here are five follow-up questions:

  1. What are the four steps involved in finding the inverse of a function?
  2. How can you verify that two functions are inverses of each other?
  3. Why do we swap xx and yy when finding the inverse?
  4. How does the slope of the original function compare with its inverse?
  5. What is the general form of an inverse for a linear function f(x)=ax+bf(x) = ax + b?

Tip: Always remember to check your work by plugging the inverse function back into the original function. If f(f1(x))=xf(f^{-1}(x)) = x, then you have found the correct inverse.

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Math Problem Analysis

Mathematical Concepts

Linear Functions
Inverse Functions

Formulas

y = mx + b
Inverse: y = (x - b) / m

Theorems

Function Inversion

Suitable Grade Level

High School