Results 1 to 2 of 2

Math Help - trig equations help?

  1. #1
    Junior Member
    Joined
    Jan 2008
    Posts
    53

    trig equations help?

    I'm stuck on these questions:

    1. Find theta in the interval 0 <theta<360 that satisfies the equation cos^2theta=sin^2theta+1

    2. 2cos^2x+2cosx-1=0
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Moo
    Moo is offline
    A Cute Angle Moo's Avatar
    Joined
    Mar 2008
    From
    P(I'm here)=1/3, P(I'm there)=t+1/3
    Posts
    5,618
    Thanks
    6
    Hello,
    Quote Originally Posted by eh501 View Post
    I'm stuck on these questions:

    1. Find theta in the interval 0 <theta<360 that satisfies the equation cos^2theta=sin^2theta+1
    recall the identity cosx+sinx=1.

    hence your equation becomes :
    1-\sin^2 \theta=\sin^2 \theta+1
    which simplifies to :
    2 \sin^2 \theta=0
    \sin \theta=0

    2. 2cos^2x+2cosx-1=0
    Let X=\cos(x)
    Solve the quadratic
    and then find the solutions ^^
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. TRIG EQUATIONS
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: November 26th 2008, 07:02 AM
  2. More Trig Equations (ugh)
    Posted in the Trigonometry Forum
    Replies: 4
    Last Post: May 9th 2008, 02:53 PM
  3. Trig Equations with Multiple Trig Functions cont.
    Posted in the Trigonometry Forum
    Replies: 4
    Last Post: April 7th 2008, 05:50 PM
  4. Trig Equations with Multiple Trig Functions help
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: April 6th 2008, 05:48 PM
  5. Trig Equations with Multiple Trig Functions
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: April 6th 2008, 03:48 PM

Search Tags


/mathhelpforum @mathhelpforum