1. The problem asks to find equations of lines that intersect the parabola $y = x^2 + 3x + 2$ a specific number of times: 0, 1, and 2 times.
2. To find the number of intersections between a line $y = mx + b$ and the parabola $y = x^2 + 3x + 2$, set them equal:
$$x^2 + 3x + 2 = mx + b$$
Rearranged:
$$x^2 + (3 - m)x + (2 - b) = 0$$
This is a quadratic equation in $x$.
3. The number of solutions (intersections) depends on the discriminant $\Delta$:
$$\Delta = (3 - m)^2 - 4 \cdot 1 \cdot (2 - b)$$
- If $\Delta > 0$, two distinct intersections.
- If $\Delta = 0$, one intersection (tangent line).
- If $\Delta < 0$, no real intersections.
4. For each case:
**a. 0 intersections:**
Choose $m$ and $b$ so that
$$\Delta < 0 \implies (3 - m)^2 < 4(2 - b)$$
Example: Let $m=0$, then
$$(3 - 0)^2 = 9 < 4(2 - b) \implies 9 < 8 - 4b \implies -4b > 1 \implies b < -\frac{1}{4}$$
Choose $b = -1$:
$$y = -1$$
This line does not intersect the parabola.
**b. 1 intersection:**
Set $\Delta = 0$:
$$(3 - m)^2 = 4(2 - b)$$
Example: Let $m=1$, then
$$(3 - 1)^2 = 4 = 4(2 - b) \implies 4 = 8 - 4b \implies -4b = -4 \implies b = 1$$
Line:
$$y = x + 1$$
This line is tangent to the parabola.
**c. 2 intersections:**
Choose $m$ and $b$ so that
$$\Delta > 0$$
Example: Let $m=0$, $b=0$:
$$(3 - 0)^2 - 4(2 - 0) = 9 - 8 = 1 > 0$$
Line:
$$y = 0$$
This line intersects the parabola twice.
Final answers:
- 0 intersections: $y = -1$
- 1 intersection: $y = x + 1$
- 2 intersections: $y = 0$
Line Parabola Intersections 29Fd4F
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