Polynomial Division 540392
1. **State the problem:** Divide the polynomial $5x^4 - 2x^2 - 13x + 8$ by $x^2 + 1$ to find the quotient and remainder.
2. **Recall the division formula:** For polynomials $f(x)$ and $g(x)$, there exist polynomials $q(x)$ (quotient) and $r(x)$ (remainder) such that:
$$f(x) = g(x) \cdot q(x) + r(x)$$
where the degree of $r(x)$ is less than the degree of $g(x)$.
3. **Set up the division:** Divide $5x^4 - 2x^2 - 13x + 8$ by $x^2 + 1$.
4. **First division step:** Divide the leading term $5x^4$ by $x^2$ to get $5x^2$.
Multiply $5x^2$ by $x^2 + 1$ to get $5x^4 + 5x^2$.
Subtract this from the original polynomial:
$$(5x^4 - 2x^2 - 13x + 8) - (5x^4 + 5x^2) = -7x^2 - 13x + 8$$
5. **Second division step:** Divide the leading term $-7x^2$ by $x^2$ to get $-7$.
Multiply $-7$ by $x^2 + 1$ to get $-7x^2 - 7$.
Subtract this from the current remainder:
$$(-7x^2 - 13x + 8) - (-7x^2 - 7) = -13x + 15$$
6. **Check remainder degree:** The remainder $-13x + 15$ has degree 1, which is less than degree 2 of divisor $x^2 + 1$, so division stops here.
7. **Final answer:**
$$\text{Quotient} = 5x^2 - 7$$
$$\text{Remainder} = -13x + 15$$