Find the equation of a line that goes through (1,-4) and is perpendicular to x=4

Question

I've tried to make m=x and then since it perpendicular I tried to switch the sign and the make 1/4 and it didn't work.

Answer 1

line x=4 is perpendicular to x-axis. So line, which is perpendicular to x=4 line, will be parallel to x-axis, therefore it is perpendicular to y-axis. Line, which is parallel to x-axis, has zero slope. Its equation, therefore, is y=0x+b or simply y=b. Since it shall pass through point (1,-4), its coordinates must satisfy the line equation. x does not matter, since there is no x in equation y=b, thus only y-coordinate matters. Plug in -4 into the equation, to obtain -4=b. So y=-4 is your answer.

 

Answer: y=-4

Answer 2

Hi Jessica;

Krill is correct.  I apologize.

Answer 3

 You are on the right track...

1.If x=4 that is simply a vertical line going straight up. Thus a line perpendicular to that would have a slope of 0.

   (Reasoning: A vertical line has an infinite slope, a slope perpendicular to that would be -1/infinity which is essentially zero)

2.(y-y₀)=m(x-x₀) is the equation of a line

3. Plug in the numbers

4. (y-(-4))=0(x-1)

5. Solve for y.  y=-4