A student claims that an ellipse has vertices at (+-3,0) and co-vertices at (0,+-7). what is the students error?

Question

tkhunny · Answer

Vertices are always farther apart than co-vertices.  "Student" has them backwards.

anonymous · Answer

yea but mathematically there is no error, Because ellipse formed will be vertical

tkhunny · Answer

If by "mathematically" you mean to include "by convention" or "according to what is written in the book" or "what the teacher wants you to know", then there is a mathematical error.  I'm not saying there is no such author, but I do not know one who has published for pre-college mathematics for the last 40 years who has held to any other definition.