Math Problem Statement

Find a formula for the inverse of the function. f(x) = e7x − 5 f −1(x)

Solution

To find the inverse of the function f(x)=e7x5f(x) = e^{7x} - 5, follow these steps:

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

y=e7x5y = e^{7x} - 5

Step 2: Solve for xx

  1. Add 5 to both sides: y+5=e7xy + 5 = e^{7x}

  2. Take the natural logarithm (ln) of both sides to remove the exponential: ln(y+5)=7x\ln(y + 5) = 7x

  3. Solve for xx by dividing both sides by 7: x=ln(y+5)7x = \frac{\ln(y + 5)}{7}

Step 3: Replace yy with xx to express the inverse function

f1(x)=ln(x+5)7f^{-1}(x) = \frac{\ln(x + 5)}{7}

Thus, the inverse function is: f1(x)=ln(x+5)7f^{-1}(x) = \frac{\ln(x + 5)}{7}

Let me know if you'd like more details on any step or clarification!


Here are five related questions:

  1. How do you verify that a function and its inverse are correct?
  2. What is the domain of the inverse function f1(x)f^{-1}(x)?
  3. How does the natural logarithm function work with exponential functions?
  4. What happens if you try to find the inverse of f(x)=ekxcf(x) = e^{kx} - c, where kk and cc are constants?
  5. How does this process change if the base of the exponential function is not ee?

Tip: When finding inverses of functions, always check that the original function is one-to-one (i.e., passes the horizontal line test). This ensures that the function has an inverse.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Inverse Functions
Exponential Functions
Logarithms

Formulas

f(x) = e^(7x) - 5
ln(y + 5) = 7x
f^(-1)(x) = ln(x + 5) / 7

Theorems

Properties of Exponential and Logarithmic Functions

Suitable Grade Level

Grades 10-12