Bunuel wrote:
In the figure above, what are the coordinates of the midpoint of PQ ?
(A) (x, y)
(B) (x, 0)
(C) (0, 0)
(D) (0, y)
(E) (-x, -y)
[Reveal] Spoiler:
For a vertical line, x always has the same value, no matter what value y takes. The equation for such a line is\(x = a\), and \(a\) is the x-intercept (what x equals when y = 0).
Here, the equation for segment PQ is x = x. That is, x takes a's place on RHS.
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