# Solve this differential equation?

GROUPS:
 (Edited to add: I may have solved my problem now. See end of post.)This does not work (edited to fix a mistake of mine): DSolve[{ 0 == -voltageC0[t] - 2*voltageC0''[t] + 2*voltageC1''[t], 0 == -voltageC1[t] - 2*voltageC1''[t] + 2*voltageC0''[t] }, voltageC0[t], t] Mathematica replies: DSolve::overdet: There are fewer dependent variables than equations, so the system is overdetermined. I cannot make sense of that response from Mathematica. I see two dependent variables, and I see two equations. Two equals two. What is the meaning of Mathematica's response to my query?Edited to add: This attempt apparently succeeds: DSolve[{ 0 == -voltageC0[t] - 2*voltageC0''[t] + 2*voltageC1''[t], 0 == -voltageC1[t] - 2*voltageC1''[t] + 2*voltageC0''[t] }, {voltageC0, voltageC1}, t] The large constant-numerical-values appearing in the solution do surprise me though.
 Gianluca Gorni 1 Vote From your equation you can deduce that voltageC0 is the same as voltageC1. You only have one differential equation with two unknowns voltage01 and voltage10.
 Thanks. I believe adding the two equations shows actually that 0==voltageC0 +voltageC1 However, when I ensure the number of equations matches the number of unkowns (as shown in my now-updated original post), I get a different cryptic error-message from Mathematica. Can anyone make sense of Mathematica's response to my query?