1. **Stating the problem:** We are given two functions:
$$f(x) = x^4 - 4x^3 + x^2 + 1$$
$$g(x) = 1 - 2x$$
and the composition:
$$f(g(x)) = x^4 - 3x^3 + 2x^2$$
We want to verify the composition and understand how $f(g(x))$ is formed.
2. **Recall the composition formula:**
The composition of functions $f$ and $g$ is defined as:
$$ (f \circ g)(x) = f(g(x)) $$
This means we substitute $g(x)$ into every $x$ in $f(x)$.
3. **Substitute $g(x)$ into $f(x)$:**
Given $g(x) = 1 - 2x$, substitute into $f(x)$:
$$ f(g(x)) = (1 - 2x)^4 - 4(1 - 2x)^3 + (1 - 2x)^2 + 1 $$
4. **Expand each term:**
- Expand $(1 - 2x)^4$ using binomial theorem:
$$ (1 - 2x)^4 = 1 - 8x + 24x^2 - 32x^3 + 16x^4 $$
- Expand $-4(1 - 2x)^3$:
$$ (1 - 2x)^3 = 1 - 6x + 12x^2 - 8x^3 $$
Multiply by $-4$:
$$ -4 + 24x - 48x^2 + 32x^3 $$
- Expand $(1 - 2x)^2$:
$$ 1 - 4x + 4x^2 $$
5. **Combine all terms:**
$$ f(g(x)) = (1 - 8x + 24x^2 - 32x^3 + 16x^4) + (-4 + 24x - 48x^2 + 32x^3) + (1 - 4x + 4x^2) + 1 $$
6. **Simplify by combining like terms:**
- Constant terms: $1 - 4 + 1 + 1 = -1$
- $x$ terms: $-8x + 24x - 4x = 12x$
- $x^2$ terms: $24x^2 - 48x^2 + 4x^2 = -20x^2$
- $x^3$ terms: $-32x^3 + 32x^3 = 0$
- $x^4$ term: $16x^4$
So,
$$ f(g(x)) = 16x^4 + 12x - 20x^2 - 1 $$
7. **Compare with given $f(g(x)) = x^4 - 3x^3 + 2x^2$:**
Our expansion does not match the given $f(g(x))$. This suggests either a different $g(x)$ or a different $f(x)$ was used in the problem statement.
**Final answer:** The composition $f(g(x))$ based on the given $f$ and $g$ is:
$$ f(g(x)) = 16x^4 + 12x - 20x^2 - 1 $$
Function Composition 96F918
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