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!

+-2npi OR +-npi How do you know which one to attach?

  1. Jan 26, 2012 #1
    1. The problem statement, all variables and given/known data

    a. tan4x=1

    If tanTheta=1, then Theta=pi/4+-npi radians.

    4x=pi/4+-npi

    x=pi/16+-npi/4

    b. sin(x+2pi)+sin(x-2pi)=1/2

    sinxcos2pi+cosxsin2pi+sinxcos2pi-sin2picosx=1/2

    2sinxcos2pi=1/2

    sinxcos2pi=1/4

    sinx=1/4

    arcsin(1/4)=0.2526+-2npi



    2. Relevant equations
    3. The attempt at a solution

    So how do you know which one to attach +-npi or +-2npi? I have a slight suspicion that it might be due to periods of trig functions, but I don't trust myself when it comes to math.

    Thanks.
     
  2. jcsd
  3. Jan 26, 2012 #2

    ehild

    User Avatar
    Homework Helper
    Gold Member

    What is the period of the tangent function, and what is the period of the sine and the cosine functions?

    ehild
     
  4. Jan 26, 2012 #3
    The tangent function repeats itself every pi and sine cosine functions repeat every 2pi?
     
  5. Jan 26, 2012 #4

    ehild

    User Avatar
    Homework Helper
    Gold Member

    Yes, correct.

    ehild
     
  6. Jan 26, 2012 #5
    Thank You, Ehild.
     
  7. Jan 26, 2012 #6

    ehild

    User Avatar
    Homework Helper
    Gold Member

    You are welcome.

    ehild
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook