How to Find $y$ Coordinate of a Point on a Line When its $x$ Coordinate is Given? [closed]
I need to find the $y$ coordinate of a point on a line for given $x$ coordinate values. Please see the following link.
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$\begingroup$If you have a line, at the first step, you should try to write down its equation. It can be done when you know the slope of the line and the coordinates of one point on that line. Also, if you know the coordinate of two points on the line then you can write its equation down.
Case 1. suppose the slope is $m$ and the point $(x_1,y_1)$ lies on the line. Hence the equation of your line will be
$$y-y_1=m(x-x_1)\tag{1}$$
Case 2. suppose you know the coordinates of two points, namely $(x_1,y_1)$ and $(x_2,y_2)$, lying on that line. First you compute the slope and then you write down the equation of the line. Hence, the equation of the line can be written as
$$y - {y_1} = {{{y_2} - {y_1}} \over {{x_2} - {x_1}}}\left( {x - {x_1}} \right)\tag{2}$$ or $$y - {y_2} = {{{y_2} - {y_1}} \over {{x_2} - {x_1}}}\left( {x - {x_2}} \right)\tag{3}$$
compare $(2)$ or $(3)$ with $(1)$. Now, for any given value $x=x_0$ you can use one of these equations to compute the $y$ coordinate for that given $x$.
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