DSolve[y'[x] + y[x] == -y[-x], y[x], x]
shift+enter后报错DSolve::litarg: To avoid possible ambiguity, the arguments of the dependent variable in {y[x]+(y^\[Prime])[x]==-y[-x]} should literally match the independent variables.
问题出在于y[-x]上，求助代码该怎么写才能求出这个方程的解k*（x-1/2）

这是楼主吧：https://mathematica.stackexchange.com/q/183870/1871