1. **Problem statement:** Find the number of intersection points of the graphs of the functions for each case.
2. **General approach:** To find the number of intersection points of $G_f$ and $G_g$, solve the equation $f(x) = g(x)$.
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**a) Given:**
$$f(x) = \frac{4}{x^2 - 2x + 2}, \quad g(x) = \frac{2}{x + 3}$$
Set equal:
$$\frac{4}{x^2 - 2x + 2} = \frac{2}{x + 3}$$
Cross-multiply:
$$4(x + 3) = 2(x^2 - 2x + 2)$$
Expand:
$$4x + 12 = 2x^2 - 4x + 4$$
Bring all terms to one side:
$$0 = 2x^2 - 4x + 4 - 4x - 12$$
$$0 = 2x^2 - 8x - 8$$
Divide both sides by 2:
$$0 = \cancel{2}x^2 - \cancel{2}4x - \cancel{2}4$$
$$0 = x^2 - 4x - 4$$
Use the quadratic formula:
$$x = \frac{4 \pm \sqrt{(-4)^2 - 4 \cdot 1 \cdot (-4)}}{2} = \frac{4 \pm \sqrt{16 + 16}}{2} = \frac{4 \pm \sqrt{32}}{2}$$
Simplify:
$$x = \frac{4 \pm 4\sqrt{2}}{2} = 2 \pm 2\sqrt{2}$$
**Number of solutions:** 2 intersection points.
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**b) Given:**
$$f(x) = \frac{3x - 7}{x - 2}, \quad g(x) = 0.6x + 2$$
Set equal:
$$\frac{3x - 7}{x - 2} = 0.6x + 2$$
Multiply both sides by $x - 2$:
$$(3x - 7) = (0.6x + 2)(x - 2)$$
Expand right side:
$$3x - 7 = 0.6x^2 - 1.2x + 2x - 4$$
$$3x - 7 = 0.6x^2 + 0.8x - 4$$
Bring all terms to one side:
$$0 = 0.6x^2 + 0.8x - 4 - 3x + 7$$
$$0 = 0.6x^2 - 2.2x + 3$$
Multiply entire equation by 5 to clear decimals:
$$0 = 3x^2 - 11x + 15$$
Calculate discriminant:
$$\Delta = (-11)^2 - 4 \cdot 3 \cdot 15 = 121 - 180 = -59 < 0$$
Since $\Delta < 0$, no real solutions.
**Number of solutions:** 0 intersection points.
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**c) Given:**
$$f(x) = \frac{1}{x - 2} + 2, \quad g(x) = \frac{4x - 15}{x - 4}$$
Set equal:
$$\frac{1}{x - 2} + 2 = \frac{4x - 15}{x - 4}$$
Multiply both sides by $(x - 2)(x - 4)$ to clear denominators:
$$(x - 4) + 2(x - 2)(x - 4) = (4x - 15)(x - 2)$$
Expand left side:
$$(x - 4) + 2(x^2 - 6x + 8) = (4x - 15)(x - 2)$$
$$x - 4 + 2x^2 - 12x + 16 = 4x^2 - 8x - 15x + 30$$
Simplify left:
$$2x^2 - 11x + 12 = 4x^2 - 23x + 30$$
Bring all terms to one side:
$$0 = 4x^2 - 23x + 30 - 2x^2 + 11x - 12$$
$$0 = 2x^2 - 12x + 18$$
Divide by 2:
$$0 = x^2 - 6x + 9$$
Factor:
$$(x - 3)^2 = 0$$
**Number of solutions:** 1 intersection point (double root at $x=3$).
Schnittpunkte Anzahl Fe9Bf4
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