how would you write this in if-then format?

Question

A line contains at least two points.

Answer 1

o yes, geometry, so last year...

If you have two points, then those two points determine a line

Answer 2

Yes, as the previous person said If line then at least 2 points.

An if-then has two parts, a predictor and a result. The predictor in this case is something being a line. The result is having at least two points.

Extra credit: There are three permutations of this if then that can be formed by switching the two parts and/or negating them. What are they and which one is logically correct (only one is and it is called the contrapositive)?

Answer 3

If there is a line, then it contains at least two points

Inverse- If there are at least 2 points, then there is one line
Converse- If there isn't a line, then there isn't at least two points
Contrapositive- If there arn't at least 2 points, then there is no line

Answer 4

If it was a line, then it would have at least two points on it.

Answer 5

If it is a line, then it has at least two points?

Answer 6

If it's a line, then is should have at least two points.
If there are two points, then a line should run through both of them.

Oh, and btw, a line has infinate points, unless of course the universe is in a loop... which I doubt.

Answer 7

You cannot put that in if-then format. If-then requires a cause and effect. A line has two points is not a cause and effect, but is a statement of fact (albeit an incorrect one).

Answer 8

NOPE, WON'T WORK. If-Then relates to logic and requires a comparator and an action. Your dialogue provides neither a comparator nor a resulting action.

Answer 9

points = array();
point p;
contains = 0;
for each p in points {
if (line.contains(p)) {
contains++;
}
}

Or this one by Eric Sink:
public bool SegmentInside(Solid s, xyz p1, xyz p2)
{
if (!PointInside(s, p1))
{
return false;
}

if (!PointInside(s, p2))
{
return false;
}

xyz v = p2 - p1;
for (double t = 0.1; t <= 0.9; t += 0.1)
{
xyz p = p1 + t * v;
if (!PointInside(s, p))
{
return false;
}
}
return true;
}