Results 1 to 8 of 8

Math Help - How do I solve this?

  1. #1
    Junior Member
    Joined
    Feb 2008
    From
    NWT, Canada
    Posts
    51

    Unhappy How do I solve this?

    The question reads Calculate the Length of PS



    Follow Math Help Forum on Facebook and Google+

  2. #2
    Bar0n janvdl's Avatar
    Joined
    Apr 2007
    From
    Meh
    Posts
    1,630
    Thanks
    6
    Quote Originally Posted by iamanoobatmath View Post
    The question reads Calculate the Length of PS



    Is the entire length of QR 10 cm?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Junior Member
    Joined
    Feb 2008
    From
    NWT, Canada
    Posts
    51
    Yes
    Follow Math Help Forum on Facebook and Google+

  4. #4
    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 iamanoobatmath View Post
    The question reads Calculate the Length of PS



    You can see that 55+35=90

    Therefore, PQR is a right angle triangle at P.

    So now, use trigonometry, for example :

    In triangle PQR :
    \cos 55=\frac{PQ}{10} \implies PQ=\dots

    Then, in triangle PQS, \sin 55=\dots

    Follow Math Help Forum on Facebook and Google+

  5. #5
    Junior Member
    Joined
    Feb 2008
    From
    NWT, Canada
    Posts
    51
    Is the answer 4.698?
    Follow Math Help Forum on Facebook and Google+

  6. #6
    Bar0n janvdl's Avatar
    Joined
    Apr 2007
    From
    Meh
    Posts
    1,630
    Thanks
    6
    Quote Originally Posted by iamanoobatmath View Post
    The question reads Calculate the Length of PS



    First notice that P = 90 degrees

    Use the Sin Rule

    \frac{Sin P}{p} = \frac{Sin Q}{q}

    \frac{Sin 90}{10} = \frac{Sin 55}{q}

    q = 8,1915 = PR

    Sin 35 = \frac{PS}{PR} = \frac{PS}{8,1915}

    PS = (8,1915) \times sin 35 = 4,6985 approx.
    Follow Math Help Forum on Facebook and Google+

  7. #7
    Bar0n janvdl's Avatar
    Joined
    Apr 2007
    From
    Meh
    Posts
    1,630
    Thanks
    6
    Quote Originally Posted by iamanoobatmath View Post
    Is the answer 4.698?
    Yes!
    Follow Math Help Forum on Facebook and Google+

  8. #8
    Math Engineering Student
    Krizalid's Avatar
    Joined
    Mar 2007
    From
    Santiago, Chile
    Posts
    3,654
    Thanks
    14
    We don't even need trig. (That does not imply the thread is posted here.)

    Some special relations in this case: \overline{PQ}^{2}=\overline{QS}\cdot \overline{QR},\,\overline{PR}^{2}=\overline{RS}\cd  ot \overline{RQ},\,\overline{PS}^{2}=\overline{SQ}\cd  ot \overline{SR}.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. need to solve summation equation to solve sum(x2)
    Posted in the Statistics Forum
    Replies: 2
    Last Post: July 16th 2010, 11:29 PM
  2. how do i solve this IVP: y'=y^2 -4
    Posted in the Differential Equations Forum
    Replies: 2
    Last Post: February 24th 2010, 12:14 PM
  3. Replies: 1
    Last Post: June 9th 2009, 11:37 PM
  4. how do i solve this?
    Posted in the Algebra Forum
    Replies: 2
    Last Post: August 2nd 2008, 03:58 PM
  5. how to solve ..
    Posted in the Advanced Algebra Forum
    Replies: 0
    Last Post: August 2nd 2008, 09:17 AM

Search Tags


/mathhelpforum @mathhelpforum