Stupid terry lee??? abscissa (1 Viewer)

[sasquatch]

Abscissae is supposed to be the x-value of a co-ordinate, but for some reasons, some questions from some textbook (terry*cough*lee*cough) refers to abscissae as the y co-ordinate.. it's strange..

BTW the dictionary says "The value of a coordinate on the horizontal axis"

Thats exactly what i though. Found the above from a different thread.

Ok the questions states that..

"The normal at and end P of the latus rectum of the ellipse x²/a² + y²/a² = 1 cuts the y-axis at M, and PN is the abscissa of P. Prove that MN = a"

Well i drew up this (see picture 1), but Terry Lee nterperates it differently (see picture 2).
View attachment 12796

Is he really wrong... because if hes not then im confused...

 

[Mill]

Could you please confirm that you typed the question correctly.

It would be a little odd for an interval, PN, to be the abscissa of a point, P.

Well... more impossible than odd.

 

[sasquatch]

ill type it again

"10. The normal at an end P of the latus rectum of the of the ellipse (see above) cuts the y-axis at M, and PN is the abscissa of P. Prove that MN = a"

There..... it is exactly as i wrote before...

So is what i did right then... meaning that terry lee used "abscissa" instead of "ordinate". Thanks.

 

[Riviet]

PN is the abscissa of P.

This is the bit that's misleading and very confusing.

Which edition is it?

 

[sasquatch]

5th edition. So did he make a mistake or... cuz nobody has given me an answer.. hehe

 

[Mill]

I guess this is open to a certain amount of interpretation.

Personally, I would suggest that you are both wrong. ^_^



I will explain what he means though.

A handy definition:
The x-coordinate of a point in a two dimensional coordinate system.

In other words, the distance along the x-axis.

Terry Lee is saying PN is the distance along the x-axis to P, at least I presume.


In any case, this is horribly worded and I wouldn't worry about it.