Results 1 to 2 of 2

Math Help - Simple Trig Simplifying

  1. #1
    Junior Member
    Joined
    Sep 2008
    Posts
    37

    Simple Trig Simplifying

    I don't know why, but I forget how to do the basics of some trig expressions because it's been so long.

    How would I go about simplifying this:

    cos(35)cos(70) - sin(35)sin(70)

    I forget how to find the values of those numbers. I don't think I have to use the calculator though, do I?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    11,742
    Thanks
    482
    \cos(a+b) = \cos{a}\cos{b} - \sin{a}\sin{b}
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 7
    Last Post: April 15th 2010, 08:12 PM
  2. Simplifying a simple algebra equation.
    Posted in the Algebra Forum
    Replies: 5
    Last Post: April 29th 2009, 01:10 PM
  3. re:simplifying trig
    Posted in the Trigonometry Forum
    Replies: 9
    Last Post: February 24th 2009, 06:07 AM
  4. Replies: 1
    Last Post: September 3rd 2008, 01:54 PM
  5. Trig...Simplifying
    Posted in the Trigonometry Forum
    Replies: 6
    Last Post: December 1st 2007, 02:56 PM

Search Tags


/mathhelpforum @mathhelpforum