Identify an equation in point-slope form for the line perpendicular to
y=1/4x-7 that passes through (-2,-6).
A. y+6= -4(x+2)
B. y+6= -1/4(x+2)
C. y+2 = -4(x+ 6)
D. y-6=1/4(x-2)

Respuesta :

Given:

Equation of line is [tex]y=\dfrac{1}{4}x-7[/tex].

The perpendicular line passes through (-2,-6).

To find:

The point slope form of perpendicular line.

Solution:

We have,

[tex]y=\dfrac{1}{4}x-7[/tex]

On comparing this equation with [tex]y=mx+b[/tex], we get

[tex]m=\dfrac{1}{4}[/tex]

Slope of given line is [tex]\dfrac{1}{4}[/tex].

Product of slopes of two perpendicular of the lines is -1.

So, [tex]Slope\times \dfrac{1}{4}=-1[/tex]

[tex]Slope=-4[/tex]

Slope of required line is -4 and it passes through (-2,-6). So, the point slope form is

[tex]y-y_1=m(x-x_1)[/tex]

where, m is slope.

[tex]y-(-6)=-4(x-(-2))[/tex]

[tex]y+6=-4(x+2)[/tex]

Therefore, the correct option is A.