Identify the equation of the line that is perpendicular to [tex][tex]$y=\frac{1}{2} x-7$[/tex][/tex] and runs through point [tex][tex]$(4,-2)$[/tex][/tex].

A. [tex][tex]$y=-2 x+6$[/tex][/tex]
B. [tex][tex]$y=\frac{1}{2} x-4$[/tex][/tex]
C. [tex][tex]$y=-\frac{1}{2} x$[/tex][/tex]
D. [tex][tex]$y=-2 x-7$[/tex][/tex]



Answer :

To identify the equation of the line that is perpendicular to [tex]\( y = \frac{1}{2} x - 7 \)[/tex] and passes through the point [tex]\( (4, -2) \)[/tex], follow these steps:

1. Determine the slope of the original line:
The given equation is in slope-intercept form [tex]\( y = mx + b \)[/tex], where [tex]\( m \)[/tex] is the slope. Hence, the slope of the original line [tex]\( y = \frac{1}{2} x - 7 \)[/tex] is [tex]\( \frac{1}{2} \)[/tex].

2. Find the slope of the perpendicular line:
The slope of a line that is perpendicular to another line is the negative reciprocal of the original slope. Therefore, the slope [tex]\( m_{\perpendicular} \)[/tex] of the perpendicular line will be:
[tex]\[ m_{\perpendicular} = -\frac{1}{\left(\frac{1}{2}\right)} = -2 \][/tex]

3. Use the point-slope form to find the equation:
The point-slope form of the equation of a line is given by:
[tex]\[ y - y_1 = m (x - x_1) \][/tex]
where [tex]\( m \)[/tex] is the slope, and [tex]\( (x_1, y_1) \)[/tex] is a point on the line. Given the point [tex]\( (4, -2) \)[/tex] and the slope [tex]\( -2 \)[/tex], plug these values into the point-slope form:
[tex]\[ y + 2 = -2(x - 4) \][/tex]

4. Simplify the equation:
Simplify the equation step by step:
[tex]\[ y + 2 = -2x + 8 \][/tex]
[tex]\[ y = -2x + 6 \][/tex]

Thus, the equation of the line that is perpendicular to [tex]\( y = \frac{1}{2} x - 7 \)[/tex] and passes through the point [tex]\( (4, -2) \)[/tex] is:
[tex]\[ \boxed{y = -2x + 6} \][/tex]