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Simultaneous equations

  1. Apr 26, 2008 #1
    [SOLVED] simultaneous equations

    Why is it that when solving some simultaneous equations two different ways you can get two different answers? One example is this:
    0=-tsin(x)+85.7sin(30) eq. 1
    0=-tcos(x)+85.7cos(30)-t eq. 2
    I solved these equations in mathematica and got t=49.4789 and x=1.0472. These were the values I submitted for an engineering assignment I recently had and I only got t correct, the correct answer for x was 60 degrees.
    So knowing which value was correct i subbed it into eq1. and i still got x=1.04723
    Then I tried using a different method. I equated both equations so eq1=eq2 and i used x=60 to solve for t and i got 49.476. Why did these two different methods yield two different values for x and how am I supposed to know which one is correct?
  2. jcsd
  3. Apr 26, 2008 #2


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    Using mathematica to solve the equations may not be helping you understand them. In the answer x=1.0472, x is expressed in radians. That IS 60 degrees.
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