You can put this solution on YOUR website!
first, recall that vertical line is parallel to y-axis and for any value of the coordinate is same
The x-coordinate of every point on the graph is . Furthermore if a point in the plane is not on the graph then its x-coordinate is not . Hence a point (,) in the plane is on the graph if and only is . Thus the equation of the vertical line through (, ) is
You can put this solution on YOUR website! The vertical line passes through (4,1) means
We want the vertical line that passes through all points with x coordinate equal to 4.
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note that the slope of a vertical line is undefined since (x2 - x1) is 0 for all points on the vertical line, for this problem (4 - 4).
note that slope is defined as (y2 - y1) / (x2 - x1)
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x = a is the equation where a is the point where the line crosses the x axis, therefore
x = 4 is the answer
