Function Study
1. **Problem:** Analyze the function $f(x) = \frac{x}{x-1}$.
- The function is a rational function with a vertical asymptote at $x=1$ because the denominator is zero there.
- The domain is all real numbers except $x=1$.
2. **Problem:** Analyze the function $f(x) = \frac{1}{x^2 - 1}$.
- Factor the denominator: $x^2 - 1 = (x-1)(x+1)$.
- Vertical asymptotes at $x=1$ and $x=-1$.
- Domain excludes $x=\pm 1$.
3. **Problem:** Analyze the polynomial $f(x) = x^3 + 3x^2 + 2x$.
- Factor: $f(x) = x(x^2 + 3x + 2) = x(x+1)(x+2)$.
- Roots at $x=0, -1, -2$.
- Domain is all real numbers.
4. **Problem:** Analyze $f(x) = \frac{1}{\sqrt{1 - x^2}}$.
- The expression under the square root must be positive: $1 - x^2 > 0 \Rightarrow -1 < x < 1$.
- Domain is $(-1,1)$.
- Vertical asymptotes at $x=\pm 1$.
5. **Problem:** Analyze $f(x) = \sqrt{1 - x^2}$.
- Domain: $1 - x^2 \geq 0 \Rightarrow -1 \leq x \leq 1$.
- Range: $[0,1]$.
6. **Problem:** Analyze $f(x) = (x^2 - 1) \log x$.
- Domain of $\log x$ is $x > 0$.
- So domain is $x > 0$.
- The factor $x^2 - 1$ is zero at $x=1$.
7. **Problem:** Analyze $f(x) = \frac{x}{e^{x-1}}$.
- Domain is all real numbers.
- Exponential in denominator never zero.
8. **Problem:** Analyze $f(x) = x^2 e^{-x}$.
- Domain is all real numbers.
- The function is a product of polynomial and exponential decay.
**Final note:** Each function is studied for domain, roots, asymptotes, and behavior.