1. **State the problem:** Find the second derivative of the function $$y = x^2 e^{2x}$$.
2. **Recall the product rule:** For two functions $u(x)$ and $v(x)$, the derivative is $$\frac{d}{dx}[uv] = u'v + uv'$$.
3. **Identify parts:** Let $$u = x^2$$ and $$v = e^{2x}$$.
4. **Find first derivatives:**
- $$u' = \frac{d}{dx} x^2 = 2x$$
- $$v' = \frac{d}{dx} e^{2x} = 2e^{2x}$$ (using chain rule).
5. **Apply product rule for first derivative:**
$$y' = u'v + uv' = 2x e^{2x} + x^2 (2 e^{2x}) = 2x e^{2x} + 2x^2 e^{2x}$$
6. **Simplify first derivative:**
$$y' = 2x e^{2x} + 2x^2 e^{2x} = 2 e^{2x} (x + x^2) = 2 e^{2x} x (1 + x)$$
7. **Find second derivative:** Differentiate $$y' = 2 e^{2x} x (1 + x)$$.
Let $$w = 2 e^{2x}$$ and $$z = x (1 + x) = x + x^2$$.
8. **Find derivatives:**
- $$w' = 2 \cdot 2 e^{2x} = 4 e^{2x}$$
- $$z' = \frac{d}{dx} (x + x^2) = 1 + 2x$$
9. **Apply product rule again:**
$$y'' = w' z + w z' = 4 e^{2x} (x + x^2) + 2 e^{2x} (1 + 2x)$$
10. **Factor out $$2 e^{2x}$$:**
$$y'' = 2 e^{2x} [2 (x + x^2) + (1 + 2x)] = 2 e^{2x} (2x + 2x^2 + 1 + 2x)$$
11. **Combine like terms:**
$$2x + 2x = 4x$$
So,
$$y'' = 2 e^{2x} (1 + 4x + 2x^2)$$
**Final answer:**
$$\boxed{y'' = 2 e^{2x} (1 + 4x + 2x^2)}$$
Second Derivative 59C225
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