In the XY-plane, line K passes through the point (1, 1) and line M passes through point (1, -1). Are lines K and m perpendicular to each other?
(1) Lines K and m intersect at the point (1, -1)
(2) Line K intersect the x-axis at the point (1, 0)
Coordinate Geometry
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Target question: Are lines K and m perpendicular to each other?[email protected] wrote:In the XY-plane, line K passes through the point (1, 1) and line M passes through point (1, -1). Are lines K and m perpendicular to each other?
(1) Lines K and m intersect at the point (1, -1)
(2) Line K intersect the x-axis at the point (1, 0)
IMPORTANT: Since line K passes through the point (1, 1), statements 1 and 2 both have the same effect of "locking" line K into exactly one position. In fact, statements 1 and 2 essentially provide the exact same information. As such, it's either the case that each statement is sufficient (D) or each statement is not sufficient (E).
Since neither statement locks line M into any certain position, line M is free to be in lots of different positions, as long as it passes through the point (1, -1)
Okay, let's jump right to . . .
Statements 1 and 2 combined:
Here are two possible scenarios that satisfy statements 1 and 2.
Scenario a:
In this instance, lines M and K are perpendicular.
Scenario b:
In this instance, lines M and K are not perpendicular.
Since we cannot answer the target question with certainty, the combined statements are NOT SUFFICIENT
Answer = E
Cheers,
Brent