Which of the following is the equation of the line that is perpendicular to [tex]$y=-\frac{1}{8} x-2$[/tex] and goes through the point [tex]$(-2,-3)$[/tex]?

Select one:
A. [tex]y=-8x-19[/tex]
B. [tex]y=\frac{1}{8} x-\frac{11}{4}[/tex]
C. [tex]y=-\frac{1}{8} x-\frac{13}{4}[/tex]
D. [tex]y=8x+13[/tex]



Answer :

To determine which of the options represents the equation of a line that is perpendicular to the given line [tex]\( y = -\frac{1}{8} x - 2 \)[/tex] and passes through the point [tex]\((-2, -3)\)[/tex], we need to follow these steps:

1. Determine the slope of the given line:
The equation of the given line is in the slope-intercept form [tex]\( y = mx + b \)[/tex], where [tex]\( m \)[/tex] is the slope. So here, [tex]\( m = -\frac{1}{8} \)[/tex].

2. Find the slope of the perpendicular line:
Perpendicular lines have slopes that are negative reciprocals of each other. If the slope of the given line is [tex]\( m_1 = -\frac{1}{8} \)[/tex], then the slope of the perpendicular line [tex]\( m_2 \)[/tex] is:
[tex]\[ m_2 = -\frac{1}{m_1} = -\frac{1}{-\frac{1}{8}} = 8 \][/tex]

3. Use the point-slope form to find the equation of the line:
The point-slope form of a line's equation is [tex]\( y - y_1 = m(x - x_1) \)[/tex], where [tex]\( (x_1, y_1) \)[/tex] is a point on the line.

We are given the point [tex]\((-2, -3)\)[/tex], and we have found the slope [tex]\( m_2 = 8 \)[/tex]. Plugging in these values:
[tex]\[ y - (-3) = 8(x - (-2)) \][/tex]
Simplify the equation:
[tex]\[ y + 3 = 8(x + 2) \][/tex]
Expand and isolate [tex]\( y \)[/tex]:
[tex]\[ y + 3 = 8x + 16 \][/tex]
[tex]\[ y = 8x + 13 \][/tex]

4. Identify the correct option:
The equation we derived is [tex]\( y = 8x + 13 \)[/tex], which corresponds to option [tex]\( d \)[/tex].

Thus, the correct answer is:
[tex]\[ \boxed{d. \ y = 8x + 13} \][/tex]