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

Capitalising trigonometric functions

  1. Dec 10, 2012 #1
    I have always capitalised the first letter of my trigonometric functions, for example, writing Sinθ as opposed to the usual sinθ. Is it wrong to capitalise them? Does it make a difference in meaning?
  2. jcsd
  3. Dec 10, 2012 #2
    It does not, however that is not common practice.
  4. Dec 11, 2012 #3


    User Avatar
    Homework Helper

    It might make a difference, depending on your convention. Restricted sine and cosine functions sometimes have the first letter capitalised. Read: http://www.cliffsnotes.com/study_guide/Inverse-Cosine-and-Inverse-Sine.topicArticleId-11658,articleId-11639.html [Broken]
    Last edited by a moderator: May 6, 2017
  5. Dec 14, 2012 #4
    I think I've heard that Sin(x) was used for a different definition of the sine function, like sin(some constant* x).

    EDIT: after looking up on the internet, I haven't found anything supporting my claim yet, so I could be wrong.
    Last edited: Dec 14, 2012
  6. Dec 14, 2012 #5


    Staff: Mentor

    In some texts, Sin(x) is the sine function restricted to its principal domain, [-##\pi/2, \pi/2##].

    Similarly, Cos(x) is the cosine function restricted to its principal domain, [0, ##\pi##].

  7. Dec 14, 2012 #6
    I've seen both Sin and Cos refer to the complex extensions of sin and cos. So it seems as if different authors use the capitalised forms for different variants.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook