若y2(x)是线性非齐次方程y'+ P(x)y=Q(x)的解,y1(x)是对应的齐次方程y'+ P(x)y=0的解,则下列函数中哪一个是y'+ P(x)y=Q(x)的解?
A. y=cy1(x)+y2(x) B. y=y1(x)+c2y2(x)
C. y=c[y1(x)+y2(x)] D. y=cy1(x)-y2(x)
已知y1(x)和y2(x)是方程y''+p(x)y'+Q(x)y=0的两个线性无关的特解, Y1(x)和Y2 (x)分别是方程y''+p(x)y'+Q(x)y=R1(x)和y''+p(x)y'+Q(x)y=R2(x)的特解。那么方程y''+p(x)y'+Q(x)y=R1(x)y+R2(x)的通解应是:
A. c1y1+c2y2B. c1Y1(x)+c2Y2(x)
C. c1y1+c2y2+Y1(x) D. c1y1+c2y2+Y1(x)+Y2(x)