New interest in Physics.

1. Mar 27, 2008

matthewmystar

Hey everyone,

I have recently developed a strong interest in physics. To the point where I am changing my major from computer science to computational physics. Anyway, I am having a problem understanding a formula in a book I have on relativity. The problem is:
90$$\circ$$ = arcsec(300/1000). Now I know some Trig. but I haven't done it in awhile and don't remember arcsec at all. Can anyone explain to me why that problem equals 90 degrees.

Thanks,
Daniel

2. Mar 27, 2008

Math Jeans

secx is equal to 1/cosx. arcsecx would then be equal to the angle that causes sec to equal x.

However, because cosx is always <= 1, then 1/cosx cannot be less than 1. Therefore, if 300/1000=3/10, arcsec(300/1000) shouldn't exist.

3. Mar 27, 2008

matthewmystar

That is was the conclusion I was coming up with also. Maybe I am misunderstanding the problem.

Last edited by a moderator: Apr 23, 2017
4. Mar 27, 2008

bassplayer142

5. Mar 27, 2008

dst

6. Mar 28, 2008

Phlogistonian

The formula should say arccotangent, not arcsecant.