1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

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


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Education Advisor

    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.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook