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!

Problem in finding the General Solution of a Trigonometric Equation v3

  1. May 19, 2017 #1
    1. The problem statement, all variables and given/known data:

    Find the general solution of the Trigonometric equation: $$3\sin ^2 {\theta} + 7\cos ^2 {\theta} =6$$

    Given andwer: ##n\pi \pm \frac {\pi}{6}##

    2. Relevant equations:

    These equations may help:

    20170519_023122.png

    3. The attempt at a solution:

    Please see the pic below:

    14951886349821598693691.jpg

    It seems correct from my side, but the answer is not matching.
     
  2. jcsd
  3. May 19, 2017 #2

    BvU

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Is there really a difference :smile: ?
     
  4. May 19, 2017 #3
    Couldn't understand.... could you explain a bit...
     
  5. May 19, 2017 #4

    BvU

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Fill in n = 1, 2, 3 in both expressions (yours and the book one) :rolleyes:
     
  6. May 19, 2017 #5

    scottdave

    User Avatar
    Homework Helper
    Gold Member

    There is a pi radian difference between -pi/6 and 5pi/6, same with pi/6 and -5pi/6. So you can just say it is +-pi/6 + n*pi, where n can be any integer. That covers all of your scenarios.
     
  7. May 19, 2017 #6

    BvU

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Why don't you let Wrichik make that discovery himself ?
     
  8. May 19, 2017 #7
    understood. Thank you.
     
  9. May 19, 2017 #8

    scottdave

    User Avatar
    Homework Helper
    Gold Member

    Thanks. I guess I didn't see your response about plugging in 1,2,3, etc when I wrote my suggestion.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted