216k views
2 votes
Answer In slope intercept form (y =Mx +b)

What is the equation of a line that is perpendicular to 2x + y = -4 and passes through the point (2, -8) thank you so much!

User Axiomer
by
9.1k points

1 Answer

3 votes

Answer: y =
(x)/(2) - 9

Explanation:

Two lines are said to be perpendicular if the product of their slope = 1 , that is , if the slope of the first line is
m_(1) and the slope of the second line is
m_(2) , then
m_(1) =
(-1)/(m_(2) ) , that is :


m_(1) X
m_(2) = -1

The line given is ; 2x + y = - 4

Make y the subject of the formula so that the equation will be in slope - intercept form ; y = mx + c

that is

y = -2x - 4

comparing with the equation of line y = mx + c , it shows that
m_(1) = -2

Since the second line is perpendicular to this line , it means
m_(1) =
(-1)/(m_(2) )

That is


m_(2) =
(1)/(2)

Using the formula y -
y_(1) = m ( x -
x_(1)) to find the equation of the line


y_(1) = -8


x_(1) = 2

substituting into the equation

y - (-8) =
(1)/(2) ( x - 2)

y + 8 =
(1)/(2) ( x- 2)

2(y+8) = x - 2

2y + 16 = x - 2

2y = x - 2 - 16

2y = x - 18

y =
(x)/(2) - 18/2

y =
(x)/(2) - 9

User Carren
by
8.3k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories