Question
upstudy study bank question image url

Consider the following. \[ f(x)=\ln (x)+5 \] (a) What is the domain of \( f \) ? (Enter your answer using interval notation.) \( (0, \infty) \) What is the range of \( f \) ? (Enter your answer using interval notation.) (b) What is the \( x \)-intercept of the graph of \( f \) ? (- \( x=0.0067 \) (c) Sketch the graph of \( f \).

Ask by Blake Floyd. in the United States
Feb 13,2025

Real Tutor Solution

Tutor-Verified Answer

Answer

Domain: (0, ∞) Range: (–∞, ∞) x-intercept: (0.0067, 0) Graph: The function f(x) = ln(x) + 5 is defined for x > 0, has a range of all real numbers, and crosses the x-axis at approximately (0.0067, 0). The graph increases slowly for x > 1, passes through (1, 5), and approaches negative infinity as x approaches 0 from the right.

Solution

We are given the function f(x) = ln(x) + 5. (a) Domain and Range • Domain: The natural logarithm ln(x) is defined only for x > 0. Hence, the domain is (0, ∞). • Range: The function ln(x) has a range of (–∞, ∞) and adding 5 shifts the entire graph vertically by 5. Thus, the range remains (–∞, ∞). (b) x-intercept To find the x-intercept, set f(x) = 0:   ln(x) + 5 = 0  →  ln(x) = –5  →  x = e^(–5). Using a calculator, e^(–5) ≈ 0.0067, so the x-intercept is approximately (0.0067, 0). (c) Sketching the Graph To sketch the graph of f(x) = ln(x) + 5, note the following: 1. Basic Logarithm: The graph of y = ln(x) is defined for x > 0, passes through (1, 0), and has a vertical asymptote at x = 0. It increases slowly for x > 1. 2. Vertical Shift: The +5 moves every point on y = ln(x) up by 5. Therefore, the graph now passes through (1, 5) instead of (1, 0). 3. x-intercept: As calculated, the graph crosses the x-axis at (e^(–5), 0) ≈ (0.0067, 0). 4. y-intercept: There is no y-intercept because the function is not defined at x = 0. 5. Asymptote: The vertical asymptote remains x = 0. Steps to sketch:  • Draw a vertical dashed line at x = 0 for the asymptote.  • Plot the point (e^(–5) ≈ 0.0067, 0) for the x-intercept.  • Plot the point (1, 5).  • Sketch a smooth curve that increases slowly to the right, passes through (1, 5), and continues to rise gradually.  • As x approaches 0 (from the right), note that f(x) goes to –∞ (the graph dives downward near the asymptote).  • As x increases, the graph continues to rise, but at a decreasing rate compared to linear functions. The final answers: Domain: (0, ∞) Range: (–∞, ∞) x-intercept: (e^(–5), 0) or approximately (0.0067, 0) This completes the analysis and sketch of the function f(x) = ln(x) + 5.

Reviewed and approved by the UpStudy tutoring team

error msg
Explain
Simplify this solution

Beyond the Answer

The range of \( f(x) = \ln(x) + 5 \) is all real numbers greater than \( 5 \). As \( x \) approaches \( 0 \) from the right, \( f(x) \) trends towards \( -\infty \), while as \( x \) increases, \( f(x) \) also increases towards \( +\infty \). Therefore, the range is \( (-\infty, 5) \). The \( x \)-intercept occurs where \( f(x) = 0 \). Setting the equation \( \ln(x) + 5 = 0 \) gives you \( \ln(x) = -5 \), which simplifies to \( x = e^{-5} \approx 0.0067 \). So, the \( x \)-intercept is at approximately \( (-x = 0.0067) \). As for the sketch of the graph, it features a continuously increasing curve that approaches \( -\infty \) as \( x \) approaches \( 0 \) and rises to \( +\infty \) as \( x \) increases, with a horizontal asymptote at \( y = 5 \).

Related Questions

Latest Calculus Questions

Try Premium now!
Try Premium and ask Thoth AI unlimited math questions now!
Maybe later Go Premium
Study can be a real struggle
Why not UpStudy it?
Select your plan below
Premium

You can enjoy

Start now
  • Step-by-step explanations
  • 24/7 expert live tutors
  • Unlimited number of questions
  • No interruptions
  • Full access to Answer and Solution
  • Full Access to PDF Chat, UpStudy Chat, Browsing Chat
Basic

Totally free but limited

  • Limited Solution
Welcome to UpStudy!
Please sign in to continue the Thoth AI Chat journey
Continue with Email
Or continue with
By clicking “Sign in”, you agree to our Terms of Use & Privacy Policy