1. **State the problem:** We need to find the area of the shaded region bounded by the lines and curve: $$y=4$$ (horizontal line), $$x=\frac{y}{4}$$ (vertical line in terms of y), and $$x=\sqrt{y}$$ (curve).
2. **Understand the boundaries:**
- The horizontal line is at $$y=4$$.
- The vertical boundary is given by $$x=\frac{y}{4}$$, which can be rewritten as $$y=4x$$.
- The curve is $$x=\sqrt{y}$$, or equivalently $$y=x^2$$.
3. **Find the intersection points:**
- Intersection of $$y=4$$ and $$x=\sqrt{y}$$:
Substitute $$y=4$$ into $$x=\sqrt{y}$$:
$$x=\sqrt{4}=2$$.
So point is $$(2,4)$$.
- Intersection of $$y=4$$ and $$x=\frac{y}{4}$$:
Substitute $$y=4$$ into $$x=\frac{y}{4}$$:
$$x=\frac{4}{4}=1$$.
So point is $$(1,4)$$.
- Intersection of $$x=\sqrt{y}$$ and $$x=\frac{y}{4}$$:
Set $$\sqrt{y} = \frac{y}{4}$$.
Square both sides:
$$y = \frac{y^2}{16}$$.
Multiply both sides by 16:
$$16y = y^2$$.
Rearrange:
$$y^2 - 16y = 0$$.
Factor:
$$y(y - 16) = 0$$.
So $$y=0$$ or $$y=16$$.
For $$y=0$$, $$x=\sqrt{0}=0$$.
For $$y=16$$, $$x=\sqrt{16}=4$$.
Since the shaded region is bounded by $$y=4$$, the relevant intersection is at $$y=0$$, $$x=0$$.
4. **Set up the integral for the area:**
The region is bounded between $$y=0$$ and $$y=4$$.
For each $$y$$ in $$[0,4]$$, the horizontal distance between the curves is:
$$\text{right boundary} - \text{left boundary} = \sqrt{y} - \frac{y}{4}$$.
5. **Calculate the area:**
$$\text{Area} = \int_0^4 \left(\sqrt{y} - \frac{y}{4}\right) dy$$.
6. **Evaluate the integral:**
$$\int_0^4 \sqrt{y} dy = \int_0^4 y^{1/2} dy = \left[ \frac{2}{3} y^{3/2} \right]_0^4 = \frac{2}{3} (4)^{3/2} - 0 = \frac{2}{3} \times 8 = \frac{16}{3}$$.
$$\int_0^4 \frac{y}{4} dy = \frac{1}{4} \int_0^4 y dy = \frac{1}{4} \left[ \frac{y^2}{2} \right]_0^4 = \frac{1}{4} \times \frac{16}{2} = \frac{1}{4} \times 8 = 2$$.
7. **Subtract to find the area:**
$$\text{Area} = \frac{16}{3} - 2 = \frac{16}{3} - \frac{6}{3} = \frac{10}{3}$$.
**Final answer:** The area of the shaded region is $$\boxed{\frac{10}{3}}$$ square units.
Shaded Area Ec9800
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