contestada

What is an equation in slope intercept form for the line perpendicular to y = - 2x + 5
that contains (-8, 1)?
1
A.O
y - 8 = 2 (x + 1)
B. O y=-2x - 1
C.O. 1
=
0:0 x = žy + 14

Respuesta :

Answer:

[tex]\displaystyle y =\frac{1}{2}x+5[/tex]

Step-by-step explanation:

Equation of the line

The slope-intercept form of a line is given by:

[tex]y=mx+b[/tex]

Being:

m = the slope of the line

b = the y-intercept

We can also use the point-slope form of the line:

[tex]y - k=m(x-h)[/tex]

Being:

(h,k) = A point that belongs to the line

Two lines of slopes m1 and m2 are perpendicular if:

[tex]m_1.m_2=-1[/tex]

We are given the line:

[tex]y=-2x+5[/tex]

Whose slope is m1=-2

Thus, the perpendicular line has a slope of:

[tex]\displaystyle m_2=-\frac{1}{m_1}[/tex]

[tex]\displaystyle m_2=-\frac{1}{-2}[/tex]

[tex]\displaystyle m_2=\frac{1}{2}[/tex]

The required line contains the point (-8,1), thus the equation is:

[tex]\displaystyle y - 1=\frac{1}{2}(x+8)[/tex]

Removing the parentheses:

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

Adding 1:

[tex]\displaystyle y =\frac{1}{2}x+\frac{1}{2}\cdot 8+1[/tex]

Operating:

[tex]\displaystyle y =\frac{1}{2}x+4+1[/tex]

[tex]\mathbf{\displaystyle y =\frac{1}{2}x+5}[/tex]