Math Problem Statement

Find the range for the function f(x) = e^x + ln(x + 3) for some c, where -2.5 ≤ c ≤ 2.

Solution

The given function is f(x)=ex+ln(x+3)f(x) = e^x + \ln(x + 3), and we need to determine the range of this function for c[2.5,2]c \in [-2.5, 2].

Steps to solve:

  1. Domain of the function:

    • The function involves ln(x+3)\ln(x + 3), which requires x+3>0x + 3 > 0, so x>3x > -3.
    • Given 2.5c2-2.5 \leq c \leq 2, x+30.5x + 3 \geq 0.5. Hence, the domain for cc is valid within this range.
  2. Behavior of each component:

    • exe^x is an increasing exponential function, and for x[2.5,2]x \in [-2.5, 2], it ranges from e2.5e^{-2.5} to e2e^2.
    • ln(x+3)\ln(x + 3) is a logarithmic function that increases as x+3x + 3 increases. For x[2.5,2]x \in [-2.5, 2], x+3[0.5,5]x + 3 \in [0.5, 5], so ln(x+3)\ln(x + 3) ranges from ln(0.5)\ln(0.5) to ln(5)\ln(5).
  3. Finding the range:

    • At x=2.5x = -2.5: f(2.5)=e2.5+ln(0.5)f(-2.5) = e^{-2.5} + \ln(0.5).
    • At x=2x = 2: f(2)=e2+ln(5)f(2) = e^2 + \ln(5).
  4. Approximations:

    • e2.50.082e^{-2.5} \approx 0.082, ln(0.5)0.693\ln(0.5) \approx -0.693. So, f(2.5)0.0820.693=0.611f(-2.5) \approx 0.082 - 0.693 = -0.611.
    • e27.389e^2 \approx 7.389, ln(5)1.609\ln(5) \approx 1.609. So, f(2)7.389+1.609=8.998f(2) \approx 7.389 + 1.609 = 8.998.

Thus, the range of f(x)f(x) for c[2.5,2]c \in [-2.5, 2] is approximately (0.611,8.998)(-0.611, 8.998).

The final answer in exact symbolic form is:

f(c)(0.611,8.998)f(c) \in (-0.611, 8.998)

Would you like more details or have any questions?

Related questions:

  1. How does the range of a logarithmic function vary with its argument?
  2. What is the behavior of the exponential function at negative values of xx?
  3. Can we generalize the range of this function for different intervals of xx?
  4. What impact does shifting the logarithmic function by 3 have on its range?
  5. How would you approach finding the range of a composite function like ex+ln(x+3)e^x + \ln(x + 3)?

Tip:

When finding the range of functions that combine exponentials and logarithms, always consider how both components behave over the interval you are interested in.

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Math Problem Analysis

Mathematical Concepts

Exponential Functions
Logarithmic Functions
Function Ranges

Formulas

f(x) = e^x + \ln(x + 3)
e^x (exponential function)
\ln(x + 3) (logarithmic function)

Theorems

Properties of exponential functions
Properties of logarithmic functions

Suitable Grade Level

Grades 10-12