1. **State the problem:** Simplify or analyze the expression $$\frac{1}{s^2(s-a)}$$ where $s$ and $a$ are variables. 2. **Formula and rules:** This is a rational expression with a polynomial denominator. Important rules: - Factor denominators fully. - Simplify by canceling common factors if possible. 3. **Intermediate work:** The denominator is already factored as $s^2(s-a)$. 4. **Explanation:** The expression cannot be simplified further unless we know specific values or relationships between $s$ and $a$. It is a rational function with vertical asymptotes at $s=0$ (of order 2) and $s=a$. 5. **Summary:** The expression is $$\frac{1}{s^2(s-a)}$$ and is simplest in this form.