- #1
ns5032
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Homework Statement
Well, I am in the middle of solving a (quite difficult) differential equation using the Method of Undetermined Coefficients, and have finally come across a system of equations and I need to solve for A(sub 1), or (A1), (A2), (B1), and (B2), but I cannot figure out how to (or if it is possible at all, seeing as how I could have done the rest of the problem wrong before it). The system of equations I now have is:
(1) -7(A1) + 3(A2) + 6(B1) - 21(B2) = 2
(2) 3(A1) + 12(A2) - 7(B1) + 3(B2) = -34
(3) 21(A1) + 5(B1) = 150
Homework Equations
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The Attempt at a Solution
Using equation (3), I can determine that
(A1) = (50/7) - (5/21)(B1)
and that
(B1) = 30 - (21/5)(A1)
Using these and plugging them into equation (2), I get a 4th equation:
(4) 1029(A1) + 420(A2) - 25(B1) + 105(B2) = 5410
Now I have a new system of equations:
(1) -7(A1) + 3(A2) + 6(B1) - 21(B2) = 2
(2) 3(A1) + 12(A2) - 7(B1) + 3(B2) = -34
(3) 21(A1) + 5(B1) = 150
(4) 1029(A1) + 420(A2) - 25(B1) + 105(B2) = 5410
Now, I tried using my calculator to solve this system, but it only gives me an error. Is there another way to solve for the coefficients?? Any help would be great!