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Homework Help: Find Sin(P + Q) from 2 equations

  1. Jul 10, 2010 #1
    1. The problem statement, all variables and given/known data
    In triangle PQR, 3SinP + 4CosQ = 6 and 4SinQ + 3CosP = 1. a) Find sin(P + Q). b) Determine the measure of angle R, in radians. The answer given for part a) is 1/2 and part b) pi/6
    2. Relevant equations
    Sin (A+B) = SinACosB + CosASinB

    3. The attempt at a solution

    Thats what I've tried and I simply don't understand how to solve it....
  2. jcsd
  3. Jul 10, 2010 #2


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    Try squaring your expressions for sin P and cos P and adding them together and simplify the resulting equation using the identity sin2 x + cos2 x = 1. I think that'll let you eventually solve for Q. Once you have Q, you can solve for P.
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