1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Malus Law - Cosine squared term?

  1. Mar 6, 2007 #1
    this is just a general trig question:

    We are going over Malus law in physics; the formula is this:
    S = s*cos^2(theta)

    My question is about the cosine squared term in the equation. does this simply mean take the cosine of a number and square it? in other words would this be the same thing as [cos(theta)]^2
     
  2. jcsd
  3. Mar 6, 2007 #2

    arildno

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    Dearly Missed

    Indeed!

    It is an unfortunate notation that confuses a lot of students, but it won't ever go away. you have to live with it.
     
  4. Mar 6, 2007 #3
    I simply tell my students that once upon a time, they wrote it as (sinx)^2, but lazy students kept leaving off the parenthesis and wrote sinx^2, sometimes meaning to take the sine of x, then square that answer; other times meaning to square the x first, then take the sine. To eliminate confusion, when they want the sin value to be squared, they put the squared symbol right next to sin
    [tex]sin^{2}x[/tex]

    So, to shorten [tex](sinx)^2[/tex] write [tex]sin^{2}x[/tex]
    and
    to shorten [tex]sin(x^2)[/tex] write [tex]sinx^2[/tex] (although some people prefer those parenthesis are left in the latter case.)
     
    Last edited: Mar 6, 2007
  5. Mar 6, 2007 #4
    ahhh...thanks for the clarification guys. you've made my day a lot easier!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Similar Discussions: Malus Law - Cosine squared term?
  1. Coefficient of a term (Replies: 6)

  2. Resursive term. (Replies: 2)

  3. Simplifying terms (Replies: 5)

  4. Find no. of terms (Replies: 9)

Loading...