Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

New interest in Physics.

  1. Mar 27, 2008 #1
    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[tex]\circ[/tex] = 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.

  2. jcsd
  3. Mar 27, 2008 #2
    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.
  4. Mar 27, 2008 #3
    That is was the conclusion I was coming up with also. Maybe I am misunderstanding the problem.
    This is the exact problem from the book:http://books.google.com/books?id=fzZMuP2sF9sC&pg=PA28&lpg=PA28&dq=arcsec(300/1000)&source=web&ots=DR72q9xmXR&sig=ZM6PZ9v6XRaqWad6pn9UxlufThQ&hl=en
  5. Mar 27, 2008 #4
  6. Mar 27, 2008 #5


    User Avatar

  7. Mar 28, 2008 #6
    The formula should say arccotangent, not arcsecant.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: New interest in Physics.
  1. New to Physics (Replies: 22)