Results 1 to 5 of 5

Math Help - solve the equation

  1. #1
    Newbie
    Joined
    Apr 2009
    Posts
    16

    solve the equation

    sin x + cos x =1 [0,360 deg)
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member
    Joined
    Dec 2008
    From
    Scotland
    Posts
    901
    Quote Originally Posted by dmak263 View Post
    sin x + cos x =1 [0,360 deg)

     \sin(x) + \cos(x) = \sqrt{2} \sin(x+45)
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Apr 2009
    Posts
    16

    thanks

    could you please explain the steps please...
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    5
    Quote Originally Posted by dmak263 View Post
    could you please explain the steps please...
    A \sin x + B \cos x can always be written in the form C \sin (x + \phi).

    So expand C \sin (x + \phi) and compare it with A \sin x + B \cos x to get equations that you can use to solve for C and \phi.


    An alternative approach to solving the original equation is given here: Solving Equations Involving Cosine Plus Sine

    Note that when using this approach you must always test the resulting solutions to see whether or not they satisfy the original equation.
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Newbie
    Joined
    Apr 2009
    Posts
    16
    thanks. I understand!!!
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. [SOLVED] Solve Differential equation for the original equation
    Posted in the Differential Equations Forum
    Replies: 5
    Last Post: February 21st 2011, 01:24 PM
  2. Solve the equation
    Posted in the Algebra Forum
    Replies: 3
    Last Post: August 9th 2010, 11:48 AM
  3. need to solve summation equation to solve sum(x2)
    Posted in the Statistics Forum
    Replies: 2
    Last Post: July 16th 2010, 10:29 PM
  4. solve equation
    Posted in the Calculus Forum
    Replies: 2
    Last Post: June 29th 2008, 08:12 AM
  5. Replies: 13
    Last Post: May 19th 2008, 08:56 AM

Search Tags


/mathhelpforum @mathhelpforum