1. The problem statement, all variables and given/known data FIND i(t). 2. Relevant equations VL = L*(di/dt) (Equation 1) IC = C*(dV/dt) (Equation 2) I(t) = e^-9*t*(A*cos(4.359*t) + B*sen(4.359*t)) A (Equation 3) 3. The attempt at a solution I can get the exact value of the constant B as shown in the answer if I use -6 after the equal sign of the integral. The problem is, I don't understand WHY it should be -6. I solved everything else correctly, but I don't understand completely how to find the second constant "B". PS: I solved the integral on Wolfram Alpha.