Write an equation that contains the given point and is perpendicular to the given line:

(4,-1), y=-8

Question

Write an equation that contains the given point and is perpendicular to the given line:

(4,-1), y=-8

mathhelp346 · Answer

I tried $$y-y _{1}=m(x-x _{1})$$ but i would always get a value for y which isnt right

anonymous · Answer

I think it is x = 4, thats the equation

mathhelp346 · Answer

how did you get that

anonymous · Answer

y = -8 is a horizontal line, the line is perpendicualr to a vertical line, get it?

mathhelp346 · Answer

yea

anonymous · Answer

so with a vertical line, x will equal one number, in this case, it is 4, always 4 for any y, so its x = 4, did i confuse u?

mathhelp346 · Answer

well how did you get x=4?

anonymous · Answer

it said that it has to contain (4, -1) so that's how I figured that x has to equal 4

anonymous · Answer

Some points of x = 4 are: (4,2)(4,8),(4,-6).......so one....understand?

mathhelp346 · Answer

so you just took the 4 from the pair?

anonymous · Answer

yup, if i included another x-value along with the pair we have, its not going to be perpendicular, that's why

mathhelp346 · Answer

oh ok thanks

anonymous · Answer

yea! Thanks :)