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!

Can you multiply the double angle forumla?

  1. Dec 1, 2012 #1
    1. The problem statement, all variables and given/known data
    I have sin4x, can I use the double angle forumla and make it 4sinxcosx???


    2. Relevant equations
    double angle forumla


    3. The attempt at a solution
    sin4x----> 4sinxcosx
     
  2. jcsd
  3. Dec 1, 2012 #2

    zyj

    User Avatar

    ...try graphing both and see if they're the same.
     
  4. Dec 1, 2012 #3

    Mark44

    Staff: Mentor

    In a word, no.
    The double-angle formula says that sin(2A) = 2*sin(A)cos(A).

    When you use formulas, you need to be very careful to follow the pattern being used.
    If you write sin(4x) as sin(2(2x)), you can use the double-angle formula, replacing A in the above by 2x.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Can you multiply the double angle forumla?
  1. Double-angle Formulae (Replies: 3)

Loading...