A.
B.
C.
D.
A.C[y1(x)-y2(x)]
B.y1(x)+C[y1(x)-y2(x)]
C.C[y1(x)+y2(x)]
D.y1(x)+C[y1(x)+y2(x)]
设φ1(x),φ2(x),φ3(x)是微分方程yˊˊ+P(x)yˊ+Q(x)y=f(x)的三个线性无关的特解,则该方程的通解为()
A.C1φ1 (x)+ C2φ2 (x)+ C3φ3 (x)
B.C1 [φ1 (x) -φ2 (x)]+ C2 [φ1 (x) -φ3 (x)]+ C3 [φ2 (x) -φ2 (x)]+ φ1 (x)
C.C1 [φ1 (x) -φ2 (x)]+ C2φ2(x)+ φ3 (x)
D.C1[φ1 (x) -φ2 (x)]+ C2[φ2 (x) -φ3 (x)]+[φ1 (x) +φ2 (x) + φ3 (x) ]
已知y1=x,y2=x+ex,y3=1+x+ex是微分方程
y"+a1(x)y'+a2(x)y=Q(x)
的解,试求此方程的通解
A.y=e-∫p(x)dx[∫q(x)e∫p(x)dxdx+C]
B.y=e∫p(x)dx∫q(x)e∫p(x)dxdx;
C.y=e∫p(x)dx[∫q(x)e-∫p(x)dxdx+C];
D.y=Ce-∫p(x)dx
矩阵方程(1.10)有解的充要条件是
AA(1)CB(1)B=C, (1.11)
并且在有解时,其通解为
X=A(1)CB(1)+Y-A(1)AYBB(1), (1.12)
其中Y∈Cn×p任意.
设y1,y2是二阶非齐次线性微分方程y''+P(x)y'+Q(x)y=F(x)的两个解, 则对应齐次方程y''+P(x)y'+Q(x)y=0的解为?