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: Trigonometry problem

  1. Oct 12, 2004 #1
    find the angle x
    if its known that:
    sin(x/2) = 1/2

  2. jcsd
  3. Oct 12, 2004 #2


    User Avatar
    Homework Helper

    why don't you simply do arcsine and arctan?
  4. Oct 12, 2004 #3
    because the whole point of the question is using trigonometric identities to solve it (believe me i would be happy to do the arctan and get it over with :smile: )
  5. Oct 12, 2004 #4


    User Avatar
    Science Advisor
    Homework Helper

    You might discover something interesting about the problem though. (It's also worth noting that that there are special angles involved.)
  6. Oct 12, 2004 #5
    i tried playing around with it

    sin(x/2) = 1/2

    i got

    tan(x) = sin(x) / cos(x) = sqrt(3)

    sin^2(x) / cos^2(x) = 3

    but that didn't really lead me anywhere
    i thought of ways to convert sin(x/2) to sin(x) with no luck
  7. Oct 12, 2004 #6


    User Avatar
    Science Advisor
    Homework Helper

    If you don't want to use the inverse trig functions directly then you may want to ponder the equilateral triangle!
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook