Find the equation of the line that is perpendicular to [tex]\( y = -2x - 9 \)[/tex] and contains the point [tex]\((8, -4)\)[/tex].

[tex]\[ y = \frac{1}{2} x - 8 \][/tex]

(Note: The correct equation for the perpendicular line needs to be entered with proper calculations and signs.)

Enter the correct symbol, + or -, that belongs in the green box.



Answer :

To determine the correct symbol for the equation of the line that is perpendicular to [tex]\( y = -2x - 9 \)[/tex] and passes through the point [tex]\( (8, -4) \)[/tex], let's follow these steps:

1. Identify the slope of the given line:
The given line equation is [tex]\( y = -2x - 9 \)[/tex]. The slope of this line ([tex]\( m_1 \)[/tex]) is [tex]\(-2\)[/tex].

2. Find the slope of the perpendicular line:
The slope of a line that is perpendicular to another is the negative reciprocal of the original slope. If [tex]\( m_1 = -2 \)[/tex], the slope of the perpendicular line ([tex]\( m_2 \)[/tex]) is given by:
[tex]\[ m_2 = -\frac{1}{m_1} = -\frac{1}{-2} = \frac{1}{2} \][/tex]

3. Use the point-slope form to find the equation of the perpendicular line:
We have a point [tex]\((x_1, y_1) = (8, -4)\)[/tex] and a slope [tex]\( m_2 = \frac{1}{2} \)[/tex].
The point-slope form of a line is:
[tex]\[ y - y_1 = m(x - x_1) \][/tex]
Substituting the given point and slope:
[tex]\[ y - (-4) = \frac{1}{2}(x - 8) \][/tex]
Simplify this equation step by step:
[tex]\[ y + 4 = \frac{1}{2}(x - 8) \][/tex]
Distribute the [tex]\(\frac{1}{2}\)[/tex]:
[tex]\[ y + 4 = \frac{1}{2}x - 4 \][/tex]
Subtract 4 from both sides to solve for [tex]\( y \)[/tex]:
[tex]\[ y = \frac{1}{2}x - 4 - 4 \][/tex]
[tex]\[ y = \frac{1}{2}x - 8 \][/tex]

4. Determine the correct symbol in the equation format [tex]\( y = [?] \frac{1}{2}x + [] \)[/tex]:
The final equation of the perpendicular line is [tex]\( y = \frac{1}{2}x - 8 \)[/tex].

The correct symbol in the green box is [tex]\( - \)[/tex].