Results 1 to 2 of 2

Math Help - Homework Help Please

  1. #1
    Member
    Joined
    Dec 2009
    Posts
    96

    Homework Help Please

    Given that sin m = 5/7 and m is in the second quadrant, what is the value of cos m?

    Please show work so I can understand this problem...
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    12,130
    Thanks
    1012
    Quote Originally Posted by KarlosK View Post
    Given that sin m = 5/7 and m is in the second quadrant, what is the value of cos m?

    Please show work so I can understand this problem...
    method 1 ...

    use the Pythagorean identity

    \sin^2{m} + \cos^2{m} = 1

    sub in the value of sin(m) and solve for cos(m). remember that cosine < 0 in quad II


    method 2 ...

    sketch a reference right triangle in quad II ... label the opposite side 5 and the hypotenuse 7. use Pythagoras to calculate the length of the adjacent side.

    cos(m) = (adjacent side)/(hypotenuse) ... remember cos(m) < 0
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. homework help
    Posted in the Discrete Math Forum
    Replies: 4
    Last Post: August 31st 2009, 05:36 AM
  2. need help with homework
    Posted in the Trigonometry Forum
    Replies: 5
    Last Post: July 20th 2009, 09:34 AM
  3. homework help
    Posted in the Algebra Forum
    Replies: 2
    Last Post: February 10th 2009, 08:12 PM
  4. Homework Help
    Posted in the Calculus Forum
    Replies: 1
    Last Post: November 2nd 2007, 02:09 PM
  5. Homework Help
    Posted in the Math Topics Forum
    Replies: 9
    Last Post: October 14th 2007, 04:00 PM

Search Tags


/mathhelpforum @mathhelpforum