Concavity Inflection
1. **Problem Statement:** We want to analyze the concavity and inflection points of the curve given by the function $$y=\frac{1}{x^2}+4$$.
2. **Formula and Rules:**
- The concavity of a function is determined by the sign of its second derivative $y''$.
- If $y''>0$, the curve is concave up.
- If $y''<0$, the curve is concave down.
- Inflection points occur where $y''=0$ or $y''$ is undefined and the concavity changes.
3. **First Derivative:**
Given $$y=\frac{1}{x^2}+4 = x^{-2} + 4,$$
we differentiate:
$$y' = -2x^{-3} = -\frac{2}{x^3}.$$
4. **Second Derivative:**
Differentiate $y'$:
$$y'' = 6x^{-4} = \frac{6}{x^4}.$$
5. **Analyze Concavity:**
Since $x^4 > 0$ for all $x \neq 0$, we have:
$$y'' = \frac{6}{x^4} > 0 \quad \text{for all } x \neq 0.$$
This means the curve is concave up everywhere except at $x=0$ where the function is undefined.
6. **Inflection Points:**
Because $y''$ never equals zero and does not change sign, there are no inflection points.
**Final answer:** The curve $$y=\frac{1}{x^2}+4$$ is concave up for all $x \neq 0$ and has no inflection points.