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!

Help with solving three equations with 3 unknowns

  1. Feb 12, 2014 #1
    I have the three following equations in the file attached:


    1. 70000000=(((R1^3)*4/3)-((R2^3)*4/3 "))(100*cosα))/(2(R1 -R2)(pi/2)(R1^4-R2^4) + 100sinα/ ((pi/4)(R1^4-R2^4))

    2. 120000000=((100*sinα))/(R1^2-R2^2)+ (100*cosα*R1 )/((pi/4)(R1^4-R2^4))

    3. m=100(pi)(R1^2-R2^2 )(cosα)* R1

    I know it looks like we have four unknowns with three equations, but I am going to assume the value of R1. Going forward, I will have the following unknowns:
    α, R2, m

    I tried solving this using Maple, but unfortunately all my values were 0. I am pretty sure I wrote it right. Otherwise, is there any other software I can use to solve this? Excel/Matlab?

    If so, which functions should I use? Are there any constraints that I will have to define?

    Thank you in advance!

    PS - I attached a picture of the formulas!
     

    Attached Files:

  2. jcsd
  3. Feb 12, 2014 #2
    Solve (1) & (2) independently as you have 2 equations with 2 unknowns then substitute into (3)

    As you know R1 & as long as R1 does NOT = R2 then I'd try multiplying (1) & (2) through by (pi/4)(R1^4-R2^4)
     
    Last edited: Feb 12, 2014
  4. Feb 13, 2014 #3
    If you wrote it like here, you made mistake. For what you use double quotes?
     
  5. Feb 13, 2014 #4
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Help with solving three equations with 3 unknowns
  1. 3 Equations 3 Unknowns (Replies: 11)

Loading...