Math Problem Statement

The function f left parenthesis x right parenthesis equals 6 x plus 5 is​ one-to-one. a. Find an equation for f Superscript negative 1​, the inverse function. b. Verify that your equation is correct by showing that f left parenthesis f Superscript negative 1 Baseline left parenthesis x right parenthesis right parenthesisequalsx and f Superscript negative 1 Baseline left parenthesis f left parenthesis x right parenthesis right parenthesisequalsx.

Solution

Let's work through the problem step by step.

a. Find the equation for the inverse function f1(x)f^{-1}(x)

We are given that f(x)=6x+5f(x) = 6x + 5. To find the inverse, follow these steps:

  1. Replace f(x)f(x) with yy: y=6x+5y = 6x + 5
  2. Swap xx and yy to solve for the inverse: x=6y+5x = 6y + 5
  3. Solve for yy (this will be f1(x)f^{-1}(x)): x5=6yx - 5 = 6y y=x56y = \frac{x - 5}{6} So, the inverse function is: f1(x)=x56f^{-1}(x) = \frac{x - 5}{6}

b. Verify the inverse function

We need to verify that:

  1. f(f1(x))=xf(f^{-1}(x)) = x
  2. f1(f(x))=xf^{-1}(f(x)) = x

1. Verify f(f1(x))=xf(f^{-1}(x)) = x

Substitute f1(x)=x56f^{-1}(x) = \frac{x - 5}{6} into f(x)f(x): f(f1(x))=6(x56)+5f(f^{-1}(x)) = 6\left( \frac{x - 5}{6} \right) + 5 Simplify: =(x5)+5=x= (x - 5) + 5 = x So, f(f1(x))=xf(f^{-1}(x)) = x.

2. Verify f1(f(x))=xf^{-1}(f(x)) = x

Substitute f(x)=6x+5f(x) = 6x + 5 into f1(x)f^{-1}(x): f1(f(x))=(6x+5)56f^{-1}(f(x)) = \frac{(6x + 5) - 5}{6} Simplify: =6x6=x= \frac{6x}{6} = x So, f1(f(x))=xf^{-1}(f(x)) = x.

Both conditions are satisfied, confirming that the inverse function f1(x)=x56f^{-1}(x) = \frac{x - 5}{6} is correct.

Would you like further details or have any questions?

Here are 5 related questions:

  1. What is the graphical interpretation of the inverse of a function?
  2. How do you determine if a function is one-to-one without graphing it?
  3. How does the horizontal line test relate to one-to-one functions?
  4. What are the conditions for a function to have an inverse?
  5. How do we handle finding the inverse of a quadratic function?

Tip: To quickly check if a function is one-to-one, see if it passes the horizontal line test: no horizontal line should intersect the graph more than once.

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Math Problem Analysis

Mathematical Concepts

Algebra
Functions
Inverse Functions

Formulas

f(x) = 6x + 5
f⁻¹(x) = (x - 5) / 6

Theorems

Inverse Function Theorem

Suitable Grade Level

Grades 10-12