1. **State the problem:** We need to evaluate the integral $$\int \frac{2}{9 + x^2} \, dx$$.
2. **Recall the formula:** The integral of $$\frac{1}{a^2 + x^2}$$ with respect to $$x$$ is $$\frac{1}{a} \arctan\left(\frac{x}{a}\right) + C$$, where $$a > 0$$.
3. **Identify constants:** Here, $$a^2 = 9$$ so $$a = 3$$.
4. **Rewrite the integral:**
$$\int \frac{2}{9 + x^2} \, dx = 2 \int \frac{1}{9 + x^2} \, dx$$
5. **Apply the formula:**
$$2 \int \frac{1}{9 + x^2} \, dx = 2 \cdot \frac{1}{3} \arctan\left(\frac{x}{3}\right) + C$$
6. **Simplify the coefficient:**
$$2 \cdot \frac{1}{3} = \frac{2}{3}$$
7. **Final answer:**
$$\int \frac{2}{9 + x^2} \, dx = \frac{2}{3} \arctan\left(\frac{x}{3}\right) + C$$
This means the integral evaluates to $$\frac{2}{3}$$ times the arctangent of $$\frac{x}{3}$$ plus the constant of integration.
Integral Arctan 3Add0B
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