1. **State the problem:** Find the average value of the function $$F(x,y) = \frac{x^2 + 2xy + y^2}{x^2 + y^2}$$ over the region in the first quadrant bounded by the coordinate axes and the line $$x + y = 2$$.
2. **Set up the region and integral:** The region is the triangle with vertices at $$(0,0), (2,0), (0,2)$$.
3. **Simplify the function:** Note that $$x^2 + 2xy + y^2 = (x + y)^2$$, so
$$F(x,y) = \frac{(x + y)^2}{x^2 + y^2}.$$
4. **Find the area of the region:** The triangle area is
$$\text{Area} = \frac{1}{2} \times 2 \times 2 = 2.$$
5. **Set up the average value formula:**
$$\text{Average} = \frac{1}{\text{Area}} \iint_{R} F(x,y) \, dA = \frac{1}{2} \int_0^2 \int_0^{2 - x} \frac{(x + y)^2}{x^2 + y^2} \, dy \, dx.$$
6. **Change to polar coordinates:** Let $$x = r \cos \theta$$, $$y = r \sin \theta$$, with $$r \geq 0$$, $$0 \leq \theta \leq \frac{\pi}{2}$$.
The boundary $$x + y = 2$$ becomes
$$r(\cos \theta + \sin \theta) = 2 \implies r = \frac{2}{\cos \theta + \sin \theta}.$$
7. **Rewrite the function in polar form:**
$$F(r, \theta) = \frac{(r \cos \theta + r \sin \theta)^2}{r^2} = \frac{r^2 (\cos \theta + \sin \theta)^2}{r^2} = (\cos \theta + \sin \theta)^2.$$
8. **Set up the integral in polar coordinates:**
$$\text{Average} = \frac{1}{2} \int_0^{\pi/2} \int_0^{\frac{2}{\cos \theta + \sin \theta}} (\cos \theta + \sin \theta)^2 r \, dr \, d\theta.$$
9. **Integrate with respect to $$r$$:**
$$\int_0^{\frac{2}{\cos \theta + \sin \theta}} r \, dr = \left[ \frac{r^2}{2} \right]_0^{\frac{2}{\cos \theta + \sin \theta}} = \frac{1}{2} \left( \frac{2}{\cos \theta + \sin \theta} \right)^2 = \frac{2}{(\cos \theta + \sin \theta)^2}.$$
10. **Substitute back:**
$$\text{Average} = \frac{1}{2} \int_0^{\pi/2} (\cos \theta + \sin \theta)^2 \times \frac{2}{(\cos \theta + \sin \theta)^2} \, d\theta = \frac{1}{2} \int_0^{\pi/2} 2 \, d\theta = \int_0^{\pi/2} 1 \, d\theta.$$
11. **Integrate with respect to $$\theta$$:**
$$\int_0^{\pi/2} 1 \, d\theta = \frac{\pi}{2}.$$
12. **Final answer:**
$$\boxed{\frac{\pi}{2}}.$$
This is the average value of $$F(x,y)$$ over the given region.
Average Value E67Eeb
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