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: What do you do if you have to evaluate arcsin2?

  1. Feb 20, 2007 #1
    what do you do if you have to evaluate arcsin2?
     
  2. jcsd
  3. Feb 20, 2007 #2

    radou

    User Avatar
    Homework Helper

    Nothing, since 2 is not in the domain.
     
  4. Feb 20, 2007 #3

    HallsofIvy

    User Avatar
    Science Advisor

    [itex]-1\le sin(x) \le 1[/itex]

    There is no x such that sin(x)= 2 and so arcsin 2 is not defined.
     
  5. Feb 21, 2007 #4

    Gib Z

    User Avatar
    Homework Helper

    Perhaps get the series for it and sub in 2, see what happens :S
     
  6. Feb 21, 2007 #5

    dextercioby

    User Avatar
    Science Advisor
    Homework Helper

    It comes down to solving the equation

    [tex] \sin x =2 [/tex]

    which has no solution in [itex] \mathbb{R} [/itex], and in [itex] \mathbb{C} [/itex] has the solution

    [tex] x=-i\ln\left(2\pm i\sqrt{3}\right)+2k\pi \ , \forall k\in\mathbb{Z} [/tex]
     
  7. Feb 21, 2007 #6

    arildno

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    Dearly Missed

    Which would diverge.
    A Pade approximant might give you some silly number, though. :smile:
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook