Math Problem Statement

Let f(x) = e^(2x + 1). (a) Determine f^(-1)(x). (b) For the function f^(-1)(x), determine (i) the domain and (ii) the range.

Solution

The given function is f(x)=e2x+1f(x) = e^{2x + 1}.

(a) Determine f1(x)f^{-1}(x), the inverse of the function.

To find the inverse, follow these steps:

  1. Start with the function y=e2x+1y = e^{2x + 1}.
  2. Switch xx and yy to find the inverse: x=e2y+1x = e^{2y + 1}
  3. Take the natural logarithm (ln) of both sides to remove the exponent: ln(x)=2y+1\ln(x) = 2y + 1
  4. Solve for yy: ln(x)1=2y\ln(x) - 1 = 2y y=ln(x)12y = \frac{\ln(x) - 1}{2} Thus, the inverse function is: f1(x)=ln(x)12f^{-1}(x) = \frac{\ln(x) - 1}{2}

(b) For the function f1(x)f^{-1}(x), determine:

(i) The domain:

Since the original function f(x)=e2x+1f(x) = e^{2x+1} is an exponential function, its range is (0,)(0, \infty). Thus, for the inverse function f1(x)f^{-1}(x), the domain is the range of the original function. Therefore, the domain of f1(x)f^{-1}(x) is: (0,)(0, \infty)

(ii) The range:

The domain of the original function f(x)=e2x+1f(x) = e^{2x + 1} is all real numbers, (,)(-\infty, \infty). Therefore, the range of the inverse function f1(x)f^{-1}(x) is also all real numbers: (,)(-\infty, \infty)

Summary:

  • f1(x)=ln(x)12f^{-1}(x) = \frac{\ln(x) - 1}{2}
  • Domain of f1(x)f^{-1}(x): (0,)(0, \infty)
  • Range of f1(x)f^{-1}(x): (,)(-\infty, \infty)

Would you like further clarification on any of these steps?


Here are some related questions you might find helpful:

  1. How do you verify that a function and its inverse are correct?
  2. What is the process for finding the inverse of other types of functions (e.g., trigonometric functions)?
  3. How do logarithmic properties help in simplifying inverse functions?
  4. What is the significance of the domain and range in inverse functions?
  5. How do the graphs of a function and its inverse relate geometrically?

Tip: Always ensure the domain and range of the original function are considered when determining the domain and range of the inverse function!

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Math Problem Analysis

Mathematical Concepts

Inverse Functions
Exponential Functions
Logarithmic Functions

Formulas

f(x) = e^(2x + 1)
f^(-1)(x) = (ln(x) - 1) / 2

Theorems

Properties of Exponential and Logarithmic Functions

Suitable Grade Level

Grades 10-12