1. **Part A: Find local minima and maxima of f(x)**
The function is given as $$f(x) = -5(x - 2)(x - 4)(x + 1)$$
2. First, expand $f(x)$ to find its derivative more easily:
$$f(x) = -5[(x - 2)(x - 4)(x + 1)]$$
Calculate $(x - 2)(x - 4) = x^2 - 6x + 8$
Then,
$$f(x) = -5(x^2 - 6x + 8)(x + 1) = -5(x^3 - 5x^2 + 2x + 8)$$
So,
$$f(x) = -5x^3 + 25x^2 - 10x - 40$$
3. Find the first derivative:
$$f'(x) = \frac{d}{dx} (-5x^3 + 25x^2 -10x - 40) = -15x^2 + 50x - 10$$
4. Find critical points by solving $f'(x) = 0$:
$$-15x^2 + 50x -10 = 0$$
Divide both sides by -5:
$$3x^2 - 10x + 2 = 0$$
Use quadratic formula:
$$x = \frac{10 \pm \sqrt{(-10)^2 - 4 \cdot 3 \cdot 2}}{2 \cdot 3} = \frac{10 \pm \sqrt{100 - 24}}{6} = \frac{10 \pm \sqrt{76}}{6}$$
Simplify $\sqrt{76} = 2\sqrt{19}$:
$$x = \frac{10 \pm 2\sqrt{19}}{6} = \frac{5 \pm \sqrt{19}}{3}$$
Approximate values:
$$x_1 \approx \frac{5 - 4.3589}{3} = 0.2137$$
$$x_2 \approx \frac{5 + 4.3589}{3} = 3.12$$
5. Determine nature of critical points using second derivative:
$$f''(x) = \frac{d}{dx} (-15x^2 + 50x - 10) = -30x + 50$$
Evaluate at $x_1$:
$$f''(0.2137) = -30 \cdot 0.2137 + 50 = -6.411 + 50 = 43.59 > 0$$ so local minimum at $x_1$.
Evaluate at $x_2$:
$$f''(3.12) = -30 \cdot 3.12 + 50 = -93.6 + 50 = -43.6 < 0$$ so local maximum at $x_2$.
6. Find coordinates of local extrema by plugging critical points into $f(x)$:
$$f(0.2137) = -5(0.2137-2)(0.2137-4)(0.2137+1)$$
Calculate:
$$0.2137-2 = -1.7863, \quad 0.2137-4 = -3.7863, \quad 0.2137+1 = 1.2137$$
Product: $-1.7863 \times -3.7863 \times 1.2137 \approx 8.208$
Then,
$$f(0.2137) = -5 \times 8.208 = -41.04$$
Similarly for maximum:
$$f(3.12) = -5(3.12-2)(3.12-4)(3.12+1)$$
Calculate:
$$3.12-2=1.12, \quad 3.12-4=-0.88, \quad 3.12+1=4.12$$
Product: $1.12 \times -0.88 \times 4.12 = -4.06$
Then,
$$f(3.12) = -5 \times -4.06 = 20.3$$
**Answer Part A:**
- Local minimum at approximately $\boxed{(0.21, -41.04)}$
- Local maximum at approximately $\boxed{(3.12, 20.3)}$
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7. **Part B: Hole of h at (c, L) and integers a, b**
Given:
$$h(x) = \frac{f(x)}{g(x)} = \frac{-5(x - 2)(x - 4)(x + 1)}{2(x - 4)(x + 3)}$$
Simplify:
$$h(x) = \frac{-5(x - 2)(x + 1)}{2(x + 3)}$$ with $x \neq 4$ (denominator zero at $x=4$)
The graph of $h$ has a hole where numerator and denominator share a factor zero, here at $x=c=4$.
Find the limit $L$:
$$L = \lim_{x\to4} h(x) = \lim_{x\to4} \frac{-5(x-2)(x+1)}{2(x+3)}$$
Evaluate directly:
$$L = \frac{-5(4-2)(4+1)}{2(4+3)} = \frac{-5 \times 2 \times 5}{2 \times 7} = \frac{-50}{14} = -\frac{25}{7} \approx -3.5714$$
We know $a < L < b$ with $a,b$ consecutive integers.
Since $-4 < -3.5714 < -3$, the integers are $oxed{a = -4, b = -3}$.
Reason: The hole coordinate has $x=4$ where original and simplified versions differ, and limit value $L$ is between consecutive integers $a$ and $b$.
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8. **Part C: Horizontal or slant asymptotes of h**
Recall:
$$h(x) = \frac{f(x)}{g(x)} = \frac{-5x^3 + 25x^2 - 10x - 40}{2x^2 + 2x - 24}$$
Degree numerator = 3, degree denominator = 2.
Since degree numerator $>$ degree denominator by 1, there is no horizontal asymptote but there is a slant (oblique) asymptote.
Find slant asymptote by polynomial division: divide numerator by denominator.
Divide:
$$\frac{-5x^3 + 25x^2 - 10x - 40}{2x^2 + 2x - 24}$$
Step 1: Leading term division:
$$-5x^3 \div 2x^2 = -\frac{5}{2}x$$
Multiply divisor by $-\frac{5}{2}x$:
$$-\frac{5}{2}x \times (2x^2 + 2x - 24) = -5x^3 - 5x^2 + 60x$$
Subtract:
$$(-5x^3 + 25x^2 -10x - 40) - (-5x^3 - 5x^2 + 60x) = 0 + 30x^2 - 70x - 40$$
Step 2: Divide leading term:
$$30x^2 \div 2x^2 = 15$$
Multiply divisor by 15:
$$15(2x^2 + 2x - 24) = 30x^2 + 30x - 360$$
Subtract:
$$(30x^2 -70x -40) - (30x^2 + 30x - 360) = 0 - 100x + 320$$
Remainder: $-100x + 320$
Slant asymptote:
$$y = -\frac{5}{2} x + 15$$
**Answer Part C:**
- No horizontal asymptotes.
- One slant asymptote: $$y = -\frac{5}{2} x + 15$$ with slope $-\frac{5}{2}$.
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**Summary:**
- Part A local extrema: minimum at $(0.21,-41.04)$, maximum at $(3.12,20.3)$.
- Part B hole at $x=4$ with $L = -\frac{25}{7} \approx -3.5714$, integers $a=-4$, $b=-3$.
- Part C slant asymptote: $y = -\frac{5}{2} x + 15$, no horizontal asymptote.
Local Extrema Hole Asymptotes
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