Results 1 to 2 of 2

Math Help - Desparate trig help needed

  1. #1
    Newbie
    Joined
    Feb 2009
    Posts
    1

    Desparate trig help needed

    I don't even know where to start with this question:

    if arccos(x)= -1 then what does the csc(x) = ?

    Also: find solutions of equation [in form of theta + 2pik, 0<theta<2pi ] for

    2cos(x)-sq.rt.of 3=0

    Again, I don't even know where to begin.

    Thanks anyone.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member
    earboth's Avatar
    Joined
    Jan 2006
    From
    Germany
    Posts
    5,830
    Thanks
    123
    Quote Originally Posted by jd981 View Post
    I don't even know where to start with this question:

    if arccos(x)= -1 then what does the csc(x) = ?
    You are supposed to know that

    \cos(\arccos(x)) = x. That means:

    x = \cos(-1)

    Since \csc(x)=\dfrac1{\sin(x)} you'll get:

    \csc(x)=\dfrac1{\sin(\cos(-1))} \approx 1.944

    Also: find solutions of equation [in form of theta + 2pik, 0<theta<2pi ] for

    2cos(x)-sq.rt.of 3=0

    ...
    2\cos(x)-\sqrt{3}=0~\implies~ \cos(x)=\frac12 \sqrt{3}~\implies~x=\frac \pi6~\vee~x=2\pi-\frac \pi6
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Trig Question - Help Needed
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: December 9th 2010, 08:24 AM
  2. trig identities help needed
    Posted in the Trigonometry Forum
    Replies: 2
    Last Post: September 4th 2010, 06:42 PM
  3. trig help needed
    Posted in the Trigonometry Forum
    Replies: 13
    Last Post: January 10th 2010, 10:22 PM
  4. Trig help needed
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: February 24th 2008, 07:12 PM
  5. Trig help needed
    Posted in the Trigonometry Forum
    Replies: 3
    Last Post: March 27th 2007, 10:56 AM

Search Tags


/mathhelpforum @mathhelpforum