Results 1 to 3 of 3

Math Help - Addition formulae

  1. #1
    Senior Member
    Joined
    Oct 2009
    Posts
    447

    Addition formulae

    With question 1 I have guessed the unknown side lengths using common pythagorean triples. Is there another way to get them?

    I have done 2a. Can I have a clue for 2b? I expect it uses addition formulae.
    Attached Thumbnails Attached Thumbnails Addition formulae-scan-1.jpg  
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Joined
    Dec 2009
    Posts
    3,120
    Thanks
    1
    Quote Originally Posted by Stuck Man View Post
    With question 1 I have guessed the unknown side lengths using common pythagorean triples. Is there another way to get them?

    I have done 2a. Can I have a clue for 2b? I expect it uses addition formulae.
    2(b) can be calculated using Sin(A-B)=SinACosB-CosASinB

    given that A=180^o and B=2x

    and Sin180^0=0 and Cos180^o=-1
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Senior Member
    Joined
    Oct 2009
    Posts
    447
    Thanks. I copied the diagram for question 1 and missed the length of QP so theres no need to reply to that now.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 4
    Last Post: July 5th 2010, 06:20 AM
  2. Addition Formulae
    Posted in the Trigonometry Forum
    Replies: 3
    Last Post: January 10th 2008, 03:43 PM
  3. trigonometry Addition Formulae (v)
    Posted in the Trigonometry Forum
    Replies: 4
    Last Post: January 7th 2007, 08:48 AM
  4. trigonometry Addition Formulae (iv)
    Posted in the Trigonometry Forum
    Replies: 3
    Last Post: January 6th 2007, 12:08 PM
  5. trigonometry Addition Formulae (ii)
    Posted in the Trigonometry Forum
    Replies: 4
    Last Post: January 5th 2007, 06:02 AM

Search Tags


/mathhelpforum @mathhelpforum