1. Limited time only! Sign up for a free 30min personal 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!

Homework Help: Solve the Equations

  1. Mar 25, 2016 #1
    1. The problem statement, all variables and given/known data
    Hi Could somebody please check my working to see if I have solved the following equations properly?

    2. Relevant equations
    1) cos2θ = sin θ
    2) sin 2θ - 1 = cos2θ

    3. The attempt at a solution
    Scanned working attached

    Attached Files:

  2. jcsd
  3. Mar 25, 2016 #2


    User Avatar
    Homework Helper
    Gold Member

    Looked okay to me on quick look.

    It is easy for you to check whether the results are correct! Just see if they work.

    It is pretty obvious they are the only solutions. But if there were ever any doubt in a problem like this, you need only do a graph from 0 to 360°.
  4. Mar 26, 2016 #3


    User Avatar
    Homework Helper

    Check if all your results are solutions.
    It would have been easier to substitute cos(2θ) with 2cos2(θ)-1.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted