• 2022-10-30
    以${{e}^{t}}$,$t{{e}^{t}}$为特解的二阶线性常系数齐次微分方程是
    A: $\frac{{{d}^{2}}x}{d{{t}^{2}}}-x=0$
    B: $\frac{{{d}^{2}}x}{d{{t}^{2}}}-2\frac{dx}{dt}+x=0$
    C: $\frac{{{d}^{2}}x}{d{{t}^{2}}}-\frac{dx}{dt}+x=0$
    D: $\frac{{{d}^{2}}x}{d{{t}^{2}}}-\frac{dx}{dt}=0$