Finding the Linear equation.

[Chipset3600]

Hello guys, i hv doubt in this question:

"1-Mark the point Q, such that the line through P (1, -2) and Q is perpendicular to the x axis (the horizontal axis) so that the point Q to point P is equidistant from the axis x. Find the equation of the line."


If the line be perpendicular of the X axis, so will be parallel of the Y axis. A line parallel to the axis Y can be a function?
OBS: Sorry about my bad technical English.

 

[Fantini]

It can't be a function, but it can be geometrically described. Its property is that the $x$ coordinate is constant. Since it has to pass through $P$, then we necessarily have $x=1$. Since it has to be equidistant to the axis, we need to find the distance of $P$ to it, which is simply the absolute value of the $y$ coordinate. By drawing a figure you can see that the solution is $Q=(1,2)$.

 

[Chipset3600]

So i guess my teacher didnt elaborate good this exercice, becos we are in Calculus 1, and we are studying as function of X

It can't be a function, but it can be geometrically described. Its property is that the $x$ coordinate is constant. Since it has to pass through $P$, then we necessarily have $x=1$. Since it has to be equidistant to the axis, we need to find the distance of $P$ to it, which is simply the absolute value of the $y$ coordinate. By drawing a figure you can see that the solution is $Q=(1,2)$.