1. **State the problem:** Convert the line equation $4x + 7y - 2 = 0$ into three forms: slope-intercept form, two-intercept form, and normal form.
2. **Slope-intercept form:** This form is $y = mx + b$, where $m$ is the slope and $b$ is the y-intercept.
Start with the given equation:
$$4x + 7y - 2 = 0$$
Isolate $y$:
$$7y = -4x + 2$$
Divide both sides by 7:
$$y = \frac{\cancel{7}7}{\cancel{7}7}y = \frac{-4}{7}x + \frac{2}{7}$$
So,
$$y = -\frac{4}{7}x + \frac{2}{7}$$
3. **Two-intercept form:** This form is $\frac{x}{a} + \frac{y}{b} = 1$, where $a$ and $b$ are the x- and y-intercepts.
Find x-intercept by setting $y=0$:
$$4x + 7(0) - 2 = 0 \Rightarrow 4x = 2 \Rightarrow x = \frac{2}{4} = \frac{1}{2}$$
Find y-intercept by setting $x=0$:
$$4(0) + 7y - 2 = 0 \Rightarrow 7y = 2 \Rightarrow y = \frac{2}{7}$$
Write the two-intercept form:
$$\frac{x}{\frac{1}{2}} + \frac{y}{\frac{2}{7}} = 1$$
4. **Normal form:** This form is $x \cos \alpha + y \sin \alpha = p$, where $p$ is the distance from the origin to the line and $\alpha$ is the angle between the normal and the x-axis.
Calculate $p$:
$$p = \frac{|c|}{\sqrt{a^2 + b^2}} = \frac{| -2 |}{\sqrt{4^2 + 7^2}} = \frac{2}{\sqrt{16 + 49}} = \frac{2}{\sqrt{65}}$$
Calculate $\cos \alpha$ and $\sin \alpha$:
$$\cos \alpha = \frac{a}{\sqrt{a^2 + b^2}} = \frac{4}{\sqrt{65}}, \quad \sin \alpha = \frac{7}{\sqrt{65}}$$
So the normal form is:
$$\frac{4}{\sqrt{65}} x + \frac{7}{\sqrt{65}} y = \frac{2}{\sqrt{65}}$$
Line Forms A4A741
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