1. The problem is to plot the graph of the function $f(x) = x - \ln x$.
2. This function is defined for $x > 0$ because the natural logarithm $\ln x$ is only defined for positive $x$.
3. To understand the shape of the graph, let's analyze the function:
- The function is $f(x) = x - \ln x$.
- The derivative is $f'(x) = 1 - \frac{1}{x}$.
4. Find critical points by setting the derivative to zero:
$$
1 - \frac{1}{x} = 0 \\
1 = \frac{1}{x} \\
x = 1
$$
5. Determine the nature of the critical point by the second derivative:
$$
f''(x) = \frac{1}{x^2} > 0 \text{ for } x > 0
$$
Since $f''(1) > 0$, the function has a local minimum at $x=1$.
6. Evaluate the function at $x=1$:
$$
f(1) = 1 - \ln 1 = 1 - 0 = 1
$$
7. Behavior as $x \to 0^+$:
$$
\lim_{x \to 0^+} f(x) = \lim_{x \to 0^+} (x - \ln x) = +\infty
$$
because $\ln x \to -\infty$.
8. Behavior as $x \to +\infty$:
$$
\lim_{x \to +\infty} f(x) = +\infty
$$
since $x$ dominates $\ln x$.
9. Summary:
- Domain: $x > 0$
- Local minimum at $(1,1)$
- $f(x) \to +\infty$ as $x \to 0^+$ and as $x \to +\infty$
This information helps to sketch the graph.
Graph Fx Ln 50A880
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.