1. **State the problem:** We need to find the equation of any line passing through the point $(-4,2)$. Then, find the equations of two lines through $(-4,2)$ whose perpendicular distance from the origin is 2.
2. **General form of a line:** The equation of a line can be written as $$Ax + By + C = 0$$ where $A$, $B$, and $C$ are constants.
3. **Condition for passing through $(-4,2)$:** Substitute $x=-4$ and $y=2$ into the line equation:
$$A(-4) + B(2) + C = 0 \Rightarrow -4A + 2B + C = 0$$
4. **Perpendicular distance from origin:** The distance $d$ from the origin $(0,0)$ to the line $Ax + By + C = 0$ is given by:
$$d = \frac{|C|}{\sqrt{A^2 + B^2}}$$
We are given $d=2$, so:
$$\frac{|C|}{\sqrt{A^2 + B^2}} = 2 \Rightarrow |C| = 2\sqrt{A^2 + B^2}$$
5. **Express $C$ from step 3:**
$$C = 4A - 2B$$
6. **Substitute $C$ into distance formula:**
$$|4A - 2B| = 2\sqrt{A^2 + B^2}$$
7. **Square both sides:**
$$ (4A - 2B)^2 = 4(A^2 + B^2) $$
Expand left side:
$$16A^2 - 16AB + 4B^2 = 4A^2 + 4B^2$$
8. **Simplify:**
$$16A^2 - 16AB + 4B^2 - 4A^2 - 4B^2 = 0 \Rightarrow 12A^2 - 16AB = 0$$
9. **Factor:**
$$4A(3A - 4B) = 0$$
So either:
- $4A=0 \Rightarrow A=0$
- or $3A - 4B=0 \Rightarrow 3A=4B \Rightarrow B=\frac{3}{4}A$
10. **Case 1: $A=0$**
From step 5, $C = 4(0) - 2B = -2B$
Distance condition:
$$|C| = 2\sqrt{A^2 + B^2} = 2|B|$$
But $|C| = |-2B| = 2|B|$, so condition holds.
Equation of line:
$$0 \cdot x + B y + C = 0 \Rightarrow B y - 2B = 0 \Rightarrow y = 2$$
11. **Case 2: $B=\frac{3}{4}A$**
Substitute into $C$:
$$C = 4A - 2B = 4A - 2 \times \frac{3}{4}A = 4A - \frac{3}{2}A = \frac{5}{2}A$$
Distance condition:
$$|C| = 2\sqrt{A^2 + B^2} = 2\sqrt{A^2 + \left(\frac{3}{4}A\right)^2} = 2|A|\sqrt{1 + \frac{9}{16}} = 2|A|\sqrt{\frac{25}{16}} = 2|A| \times \frac{5}{4} = \frac{5}{2}|A|$$
Since $|C| = \frac{5}{2}|A|$, condition holds.
Equation of line:
$$A x + B y + C = 0 \Rightarrow A x + \frac{3}{4}A y + \frac{5}{2}A = 0$$
Divide both sides by $A$ (assuming $A \neq 0$):
$$x + \frac{3}{4} y + \frac{5}{2} = 0$$
Multiply through by 4 to clear fractions:
$$4x + 3y + 10 = 0$$
12. **Final answers:**
- Line 1: $$y = 2$$
- Line 2: $$4x + 3y + 10 = 0$$
These are the two lines through $(-4,2)$ whose perpendicular distance from the origin is 2.
Lines Through Point 285Fc7
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