1. **Problem 1a:** Find the area bounded by the curves $f(x) = 2x - x^2$ and $g(x) = x - 2$.
2. **Find the points of intersection:** Solve $2x - x^2 = x - 2$.
$$2x - x^2 = x - 2$$
$$-x^2 + 2x - x + 2 = 0$$
$$-x^2 + x + 2 = 0$$
Multiply both sides by $-1$:
$$\cancel{-}x^2 + x + 2 = 0 \Rightarrow x^2 - x - 2 = 0$$
3. **Factor the quadratic:**
$$x^2 - x - 2 = (x - 2)(x + 1) = 0$$
4. **Solutions:**
$$x = 2 \quad \text{or} \quad x = -1$$
5. **Set up the integral for the area:**
The area $A$ between two curves $f(x)$ and $g(x)$ from $a$ to $b$ is
$$A = \int_a^b |f(x) - g(x)| \, dx$$
Since $f(x) = 2x - x^2$ and $g(x) = x - 2$, check which is on top between $x=-1$ and $x=2$.
At $x=0$:
$$f(0) = 0, \quad g(0) = -2$$
So $f(x) \ge g(x)$ in this interval.
6. **Calculate the area:**
$$A = \int_{-1}^2 \bigl( (2x - x^2) - (x - 2) \bigr) dx = \int_{-1}^2 (-x^2 + x + 2) dx$$
7. **Integrate:**
$$\int (-x^2 + x + 2) dx = -\frac{x^3}{3} + \frac{x^2}{2} + 2x + C$$
8. **Evaluate definite integral:**
$$A = \left[-\frac{x^3}{3} + \frac{x^2}{2} + 2x \right]_{-1}^2$$
Calculate at $x=2$:
$$-\frac{8}{3} + 2 + 4 = -\frac{8}{3} + 6 = \frac{10}{3}$$
Calculate at $x=-1$:
$$-\frac{-1}{3} + \frac{1}{2} - 2 = \frac{1}{3} + \frac{1}{2} - 2 = \frac{2}{6} + \frac{3}{6} - 2 = \frac{5}{6} - 2 = -\frac{7}{6}$$
9. **Subtract:**
$$A = \frac{10}{3} - \left(-\frac{7}{6}\right) = \frac{10}{3} + \frac{7}{6} = \frac{20}{6} + \frac{7}{6} = \frac{27}{6} = \frac{9}{2} = 4.5$$
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"subject": "calculus",
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"desmos": {"latex": "y=2x - x^2", "features": {"intercepts": true, "extrema": true}},
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Area Bounded 1A 6376Af
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