Ansatz für die charakteristische Gleichung
λ2+2λ+2=0{\displaystyle \lambda ^{2}+2\lambda +2=0}
λ1=−1+i{\displaystyle \lambda _{1}=-1+i}
λ2=−1−i{\displaystyle \lambda _{2}=-1-i}
yh(x)=e−x(C1cosx+C2sinx)=C1cosxex+C2sinxex{\displaystyle y_{h}(x)=e^{-x}(C_{1}\cos {x}+C_{2}\sin {x})={\frac {C_{1}\cos {x}}{e^{x}}}+{\frac {C_{2}\sin {x}}{e^{x}}}}
Nun Differenzieren
yh′(x)=−C1cosx−C2cosx+(C1+C2)sinxex{\displaystyle y_{h}'(x)=-{\frac {C_{1}\cos {x}-C_{2}\cos {x}+(C_{1}+C_{2})\sin {x}}{e^{x}}}}
Einsetzen für
y′(0)=0{\displaystyle y'(0)=0}
yh′(0)=−C1cos0−C2cos0+(C1+C2)sin0e0=C1cos0−C2cos0+(C1+C2)sin0=C1cos0−C2cos0=C1−C2{\displaystyle y_{h}'(0)=-{\frac {C_{1}\cos {0}-C_{2}\cos {0}+(C_{1}+C_{2})\sin {0}}{e^{0}}}=C_{1}\cos {0}-C_{2}\cos {0}+(C_{1}+C_{2})\sin {0}=C_{1}\cos {0}-C_{2}\cos {0}=C_{1}-C_{2}}
C1=C2{\displaystyle C_{1}=C_{2}}
y(0)=1{\displaystyle y(0)=1}
Nun Einsetzen für y(0)=1{\displaystyle y(0)=1}
yh(1)=1=C1cos0e0+C2sin0e0=C1cos0=C1{\displaystyle y_{h}(1)=1={\frac {C_{1}\cos {0}}{e^{0}}}+{\frac {C_{2}\sin {0}}{e^{0}}}=C_{1}\cos {0}=C_{1}}
Daraus folgt:
C1=C2=1{\displaystyle C_{1}=C_{2}=1}
y(x)=cosx+sinxex{\displaystyle y(x)={\frac {\cos {x}+\sin {x}}{e^{x}}}}