【名词&注释】
微分方程(differential equation)
[单选题]已知y1(x)与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)+R2(x)的通解应是:()
A. c1y1+c2y2
B. c1Y1(x)+c2Y2(x)
C. c1y1+c2y2+Y1(x)
D. c1y1+c2y2+Y1(x)+Y2(x)