1. The problem statement, all variables and given/known data This topic is under linear system differential equation.Solve the system by using exponential method. Just want to ask the expansion of exponential function 2. Relevant equations e^x=1+x+(x^2)/2!+(x^3)/3!+........ 3. The attempt at a solution then how about the e^(-x)=? Besides what is the function of sin x and cos x in continued function (such in e^x)? Thanks!