Answer:
Step-by-step explanation:
Given the line L1 as y = 2x perpendicular to an unknown line L2 passing through the point P = (1, 2), we are to find the equation of line L2. to find the equation of the line L2, we will use the point-slope equation of a line expressed as y-y₀ = m(x-x₀)
m is the slope of the unknown line
(x₀, y₀) is the given point.
First is to get the slope of the known line:
comparing the line L1: y = 2x with the standard equation of the line y = mx+c, it can be seen that m = 2
Then we will calculate the slope of the required line.
Since L1 is perpendicular to L2, the product of their slope will be -1 i.e
mm₁ = -1 where m₁ is the slope of the required line L2.
Given m =2
m₁ = -1/m
m₁ = -1/2
Finally we will calculate the equation of line L2 by substituting the slope of line L2 and the point in the point slope equation above;
y-y₀ = m(x-x₀)
Given (x₀, y₀) = (1,2) and m₁ = -1/2
y-2 = -1/2(x-1)
open the parenthesis
y-2 = -x/2+1/2
multiply through by 2:
2y-4 = -x+1
2y+x = 1+4
2y+x = 5
Hence the equation of the line L2 is 2y+x = 5
